diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index 9b70a5a..a16d77f 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -1,6 +1,6 @@
 # Implementation Plan: Sequence Placement and Composition
 
-Status: implementation in progress; stages 1–5 completed.
+Status: implementation in progress; stages 1–6 completed.
 
 ## Purpose and authority
 
@@ -414,6 +414,20 @@ Scope: `imports.go`, `load_input.go`, `load_request.go`, and their handoffs.
 Validation: import/destination/grouped/source-version/resource-context tests and
 `./scripts/check.sh`. Completion: this is a behavior-preserving private refactor.
 
+Completion evidence: acquisition now retains ordered ordinary-mapping scopes
+with source-local payloads, placed contributions, destinations, source records,
+and source-version processing results. Underlay groups compose those acquired
+contributions at their boundary instead of treating retained history values as
+complete roots. Existing filesystem contexts, import traversal/repetition
+state, load-wide accounting, hooks, and lifecycle handling remain in their
+existing paths. These checks passed with Go `go1.26.9 linux/amd64`:
+
+- `GOTOOLCHAIN=local GOPROXY=off go test ./internal/engine -run 'Destination|Import|Grouped|SourceVersion|Resource' -count=1`
+- `GOTOOLCHAIN=local ./scripts/check.sh`
+- `git diff --check`
+
+No environmental limitation affected validation; checks ran on Linux/amd64.
+
 ## Stage 7 — Add the private item-placement operation and accounting
 
 Scope: placement primitives and engine per-input options; not public exposure.
diff --git a/internal/engine/compose.go b/internal/engine/compose.go
index b079a32..1cf4b4d 100644
--- a/internal/engine/compose.go
+++ b/internal/engine/compose.go
@@ -7,6 +7,7 @@ import "gitea.maximumdirect.net/eric/ConfigKit/internal/document"
 // origins retain every source that contributes to a composite mapping.
 type composedDocument struct {
 	root           *document.Node
+	acquisition    []acquisitionScope
 	claims         []compositionClaim
 	sequenceRanges []sequenceRange
 	origins        map[string]Origin
@@ -46,6 +47,7 @@ func newAssemblyAccumulator(owned *composedDocument) *assemblyAccumulator {
 func cloneComposedDocument(base *composedDocument) *composedDocument {
 	return &composedDocument{
 		root: document.Clone(base.root), claims: cloneCompositionClaims(base.claims),
+		acquisition:    cloneAcquisitionScopes(base.acquisition),
 		sequenceRanges: cloneSequenceRanges(base.sequenceRanges),
 		origins:        cloneOriginIndex(base.origins), overlays: cloneOverlayRecords(base.overlays),
 		applications: cloneHistoryApplications(base.applications),
diff --git a/internal/engine/destination_import_test.go b/internal/engine/destination_import_test.go
index da51370..2a1de96 100644
--- a/internal/engine/destination_import_test.go
+++ b/internal/engine/destination_import_test.go
@@ -4,6 +4,8 @@ import (
 	"path/filepath"
 	"testing"
 	"testing/fstest"
+
+	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
 )
 
 type importDestinationConfig struct {
@@ -133,7 +135,11 @@ parent: true
 		}
 	}
 
-	composed, diagnostics := composeDocuments(state.documents...)
+	documents := make([]*document.Node, 0, len(state.scope.contributions))
+	for _, contribution := range state.scope.contributions {
+		documents = append(documents, contribution.document)
+	}
+	composed, diagnostics := composeDocuments(documents...)
 	if len(diagnostics) != 0 {
 		t.Fatalf("composition diagnostics = %#v", diagnostics)
 	}
diff --git a/internal/engine/imports.go b/internal/engine/imports.go
index 8ed0907..06af12e 100644
--- a/internal/engine/imports.go
+++ b/internal/engine/imports.go
@@ -51,11 +51,11 @@ type importTraversal struct {
 	rule         *VersionRule
 	versionState *sourceVersionState
 
-	documents []*document.Node
-	sources   []SourceInfo
-	active    map[resourceIdentity]int
-	visited   map[resourceIdentity]importRoute
-	stack     []importRoute
+	scope   acquisitionScope
+	sources []SourceInfo
+	active  map[resourceIdentity]int
+	visited map[resourceIdentity]importRoute
+	stack   []importRoute
 }
 
 func loadImportedDocuments(source Source, context *FilesystemContext, main parsedSource, rule *VersionRule, limits importLimits) (*composedDocument, []SourceInfo, []Diagnostic) {
@@ -144,9 +144,9 @@ func loadImportedWithAccessTrackedAndProcessing(access *filesystemAccess, basePa
 	accounting.nodes += countInputNodes(main.document)
 	state := importTraversal{
 		access: access, accounting: accounting, limits: limits, rule: rule, versionState: versionState,
-		documents: make([]*document.Node, 0, 1),
-		sources:   []SourceInfo{mainInfo},
-		active:    make(map[resourceIdentity]int), visited: visited,
+		scope:   acquisitionScope{destination: destination.clone()},
+		sources: []SourceInfo{mainInfo},
+		active:  make(map[resourceIdentity]int), visited: visited,
 	}
 	if state.visited == nil {
 		state.visited = make(map[resourceIdentity]importRoute)
@@ -182,7 +182,10 @@ func loadImportedWithAccessTrackedAndProcessing(access *filesystemAccess, basePa
 			diagnostics = []Diagnostic{importDiagnostic(CodeImportLimitExceeded, "configuration exceeds the aggregate node limit", nil)}
 		} else {
 			accounting.nodes += placementNodes
-			state.documents = append(state.documents, placed)
+			state.scope.contributions = append(state.scope.contributions, acquiredContribution{
+				source: cloneSourceInfo(mainInfo), payload: body, document: placed,
+				destination: destination.clone(), processing: processing,
+			})
 			diagnostics = state.walkDeclarations(basePath, declarations, 0, destination)
 		}
 	}
@@ -194,8 +197,13 @@ func loadImportedWithAccessTrackedAndProcessing(access *filesystemAccess, basePa
 	if closeErr != nil {
 		return nil, cloneSourceInfos(state.sources), []Diagnostic{importDiagnostic(CodeImportRead, "configuration root could not be closed", nil)}
 	}
-	composed, diagnostics := composeDocuments(state.documents...)
+	documents := make([]*document.Node, 0, len(state.scope.contributions))
+	for _, contribution := range state.scope.contributions {
+		documents = append(documents, contribution.document)
+	}
+	composed, diagnostics := composeDocuments(documents...)
 	if composed != nil {
+		composed.acquisition = []acquisitionScope{cloneAcquisitionScope(state.scope)}
 		composed.inputBytes = accounting.bytes
 		composed.inputNodes = accounting.nodes
 	}
@@ -237,20 +245,20 @@ func (s *importTraversal) walkDeclarations(basePath string, declarations []impor
 				matched := declaration
 				matched.path = match
 				matched.glob = ""
-				if diagnostics := s.visitPath(basePath, matched, childDestination, depth+1); len(diagnostics) != 0 {
+				if diagnostics := s.visitPath(basePath, matched, childDestination, declaration.destination, depth+1); len(diagnostics) != 0 {
 					return diagnostics
 				}
 			}
 			continue
 		}
-		if diagnostics := s.visitPath(basePath, declaration, childDestination, depth+1); len(diagnostics) != 0 {
+		if diagnostics := s.visitPath(basePath, declaration, childDestination, declaration.destination, depth+1); len(diagnostics) != 0 {
 			return diagnostics
 		}
 	}
 	return nil
 }
 
-func (s *importTraversal) visitPath(basePath string, declaration importDeclaration, destination Path, depth int) []Diagnostic {
+func (s *importTraversal) visitPath(basePath string, declaration importDeclaration, destination, relativeDestination Path, depth int) []Diagnostic {
 	location := declaration.location
 	if depth > s.limits.depth {
 		return []Diagnostic{importDiagnostic(CodeImportLimitExceeded, "configuration exceeds the active import-depth limit", &location)}
@@ -334,11 +342,13 @@ func (s *importTraversal) visitPath(basePath string, declaration importDeclarati
 	var body *document.Node
 	var declarations []importDeclaration
 	var diagnostics []Diagnostic
+	var processing *sourceVersionProcessingResult
 	if s.versionState != nil && s.versionState.mode != sourceVersionModeDefault {
 		processed, failures := s.versionState.process(root, sourceVersionContribution, destination, sourceID)
 		if len(failures) != 0 {
 			return failures
 		}
+		processing = &processed
 		body, declarations = processed.payload, processed.imports
 	} else {
 		body, declarations, diagnostics = splitImportDirectives(root)
@@ -368,7 +378,10 @@ func (s *importTraversal) visitPath(basePath string, declaration importDeclarati
 	}
 
 	route := importRoute{canonical: canonical, locations: currentRoute.locations}
-	s.documents = append(s.documents, placed)
+	s.scope.contributions = append(s.scope.contributions, acquiredContribution{
+		source: cloneSourceInfo(info), payload: body, document: placed,
+		destination: destination.clone(), relativeDestination: relativeDestination.clone(), processing: processing,
+	})
 	s.active[identity] = len(s.stack)
 	s.visited[identity] = route
 	s.stack = append(s.stack, route)
diff --git a/internal/engine/load_input.go b/internal/engine/load_input.go
index a8b702f..fc818d2 100644
--- a/internal/engine/load_input.go
+++ b/internal/engine/load_input.go
@@ -11,12 +11,58 @@ type assembledInput struct {
 	parsed       parsedSource
 	document     *document.Node
 	composition  *composedDocument
+	acquisition  []acquisitionScope
 	inheritance  *inheritanceScope
 	sources      []SourceInfo
 	contexts     map[string]ResourceContext
 	versionState *sourceVersionState
 }
 
+// acquiredContribution keeps a source-local payload beside its placed document.
+// The latter is used for composition; the former preserves the acquisition
+// boundary for later scoped assembly and evidence.
+type acquiredContribution struct {
+	source              SourceInfo
+	payload             *document.Node
+	document            *document.Node
+	destination         Path
+	relativeDestination Path
+	processing          *sourceVersionProcessingResult
+}
+
+// acquisitionScope is the ordered strict mapping scope produced by one input
+// and its ordinary imports.
+type acquisitionScope struct {
+	destination   Path
+	contributions []acquiredContribution
+}
+
+func cloneAcquisitionScope(scope acquisitionScope) acquisitionScope {
+	cloned := acquisitionScope{destination: scope.destination.clone()}
+	if scope.contributions != nil {
+		cloned.contributions = make([]acquiredContribution, len(scope.contributions))
+		for index, contribution := range scope.contributions {
+			cloned.contributions[index] = acquiredContribution{
+				source: cloneSourceInfo(contribution.source), payload: contribution.payload,
+				document: contribution.document, destination: contribution.destination.clone(),
+				relativeDestination: contribution.relativeDestination.clone(), processing: contribution.processing,
+			}
+		}
+	}
+	return cloned
+}
+
+func cloneAcquisitionScopes(scopes []acquisitionScope) []acquisitionScope {
+	if scopes == nil {
+		return nil
+	}
+	cloned := make([]acquisitionScope, len(scopes))
+	for index, scope := range scopes {
+		cloned[index] = cloneAcquisitionScope(scope)
+	}
+	return cloned
+}
+
 func assembleBaseInput[T any](source Source, options Options[T]) (assembledInput, []Diagnostic) {
 	return assembleBaseInputTracked(source, options, Path{}, &importAccounting{}, nil, nil)
 }
@@ -76,6 +122,7 @@ func assembleBaseInputTrackedForRole[T any](source Source, options Options[T], d
 		if len(diagnostics) != 0 {
 			return input, diagnostics
 		}
+		input.acquisition = cloneAcquisitionScopes(input.composition.acquisition)
 		input.document = input.composition.root
 	} else {
 		input.sources = sourceInfos(parsed.source)
@@ -93,7 +140,15 @@ func assembleBaseInputTrackedForRole[T any](source Source, options Options[T], d
 		if err != nil {
 			return input, []Diagnostic{sourceDiagnostic(CodeSourceLimitExceeded, parsed.source.ID, "configuration exceeds the source depth or node limit after destination placement")}
 		}
+		localPayload := input.document
 		input.document = placed
+		input.acquisition = []acquisitionScope{{
+			destination: destination.clone(),
+			contributions: []acquiredContribution{{
+				source: cloneSourceInfo(*parsed.source), payload: localPayload,
+				document: placed, destination: destination.clone(), processing: versionProcessing,
+			}},
+		}}
 		rawNodes := countInputNodes(parsed.document)
 		placementNodes := destinationWrapperNodeCount(destination)
 		if accounting.sources+1 > limits.sources || accounting.bytes+parsed.bytes > limits.bytes || accounting.nodes+rawNodes+placementNodes > limits.nodes {
@@ -185,5 +240,6 @@ func compositionForInput(input assembledInput) (*composedDocument, []Diagnostic)
 	}
 	composition.inputBytes = input.parsed.bytes
 	composition.inputNodes = countInputNodes(input.document)
+	composition.acquisition = cloneAcquisitionScopes(input.acquisition)
 	return composition, nil
 }
diff --git a/internal/engine/load_request.go b/internal/engine/load_request.go
index 1865dcb..d841550 100644
--- a/internal/engine/load_request.go
+++ b/internal/engine/load_request.go
@@ -161,7 +161,7 @@ func acquireUnderlayGroupWithVersion(group loadGroup, index int, rule *VersionRu
 	initialBytes, initialNodes := accounting.bytes, accounting.nodes
 	visited := make(map[resourceIdentity]importRoute)
 	hostToken := &namespaceToken{}
-	var documents []*document.Node
+	var scopes []acquisitionScope
 	var sources []SourceInfo
 	var contexts map[string]ResourceContext
 	for _, contribution := range group.inputs {
@@ -186,12 +186,12 @@ func acquireUnderlayGroupWithVersion(group loadGroup, index int, rule *VersionRu
 				Message: "underlay inputs cannot contribute to the schema-version path", Primary: &location,
 			}}
 		}
-		if acquired.composition != nil {
-			for _, application := range acquired.composition.applications {
-				documents = append(documents, application.value)
-			}
-		} else {
-			documents = append(documents, acquired.document)
+		scopes = append(scopes, cloneAcquisitionScopes(acquired.acquisition)...)
+	}
+	var documents []*document.Node
+	for _, scope := range scopes {
+		for _, contribution := range scope.contributions {
+			documents = append(documents, contribution.document)
 		}
 	}
 	if len(documents) == 0 {
@@ -203,6 +203,7 @@ func acquireUnderlayGroupWithVersion(group loadGroup, index int, rule *VersionRu
 	}
 	composition.inputBytes = accounting.bytes - initialBytes
 	composition.inputNodes = accounting.nodes - initialNodes
+	composition.acquisition = cloneAcquisitionScopes(scopes)
 	for pointer, origin := range composition.origins {
 		origin.Layer = LayerUnderlay
 		composition.origins[pointer] = origin