diff --git a/src/main/java/edu/ohsu/cmp/ecp/sds/SupplementalDataStoreLinkingInterceptor.java b/src/main/java/edu/ohsu/cmp/ecp/sds/SupplementalDataStoreLinkingInterceptor.java
index 23961c6..cf549f6 100644
--- a/src/main/java/edu/ohsu/cmp/ecp/sds/SupplementalDataStoreLinkingInterceptor.java
+++ b/src/main/java/edu/ohsu/cmp/ecp/sds/SupplementalDataStoreLinkingInterceptor.java
@@ -294,7 +294,7 @@ PatientCompartmentLinkingContext compartmentAlreadyExists( IIdType patientCompar
 		PatientCompartmentLinkingContext nonLocalCompartmentIsAlreadyLinked( IIdType nonLocalPatientCompartment ) {
 			if ( !nonLocalCompartments.contains( nonLocalPatientCompartment ) )
 				new IllegalArgumentException( "cannot identify non-local compartment \"" + nonLocalPatientCompartment + "\" as already linked because the local compartment has not been identified yet" ) ;
-			this.linkedNonLocalCompartments.add( basisCompartment ) ;
+			this.linkedNonLocalCompartments.add( nonLocalPatientCompartment ) ;
 			return this ;
 		}
 	}
diff --git a/src/test/java/edu/ohsu/cmp/ecp/sds/PatientAppClientSimulationTest.java b/src/test/java/edu/ohsu/cmp/ecp/sds/PatientAppClientSimulationTest.java
new file mode 100644
index 0000000..078d7dd
--- /dev/null
+++ b/src/test/java/edu/ohsu/cmp/ecp/sds/PatientAppClientSimulationTest.java
@@ -0,0 +1,139 @@
+package edu.ohsu.cmp.ecp.sds;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.hasSize;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.BiConsumer;
+
+import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.instance.model.api.IIdType;
+import org.hl7.fhir.r4.model.Condition;
+import org.hl7.fhir.r4.model.IdType;
+import org.hl7.fhir.r4.model.Linkage;
+import org.hl7.fhir.r4.model.Observation;
+import org.hl7.fhir.r4.model.Reference;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ActiveProfiles;
+
+import ca.uhn.fhir.jpa.starter.AppTestMockPermissionRegistry;
+import ca.uhn.fhir.jpa.starter.AppTestMockPrincipalRegistry;
+import ca.uhn.fhir.rest.client.api.IGenericClient;
+import edu.ohsu.cmp.ecp.sds.assertions.PartitionAssertions;
+import edu.ohsu.cmp.ecp.sds.assertions.SdsAssertions;
+import edu.ohsu.cmp.ecp.sds.util.SdsPartitionOperations;
+import edu.ohsu.cmp.ecp.sds.util.SdsPartitionOperations.IdGenerationStrategy;
+import junit.framework.AssertionFailedError;
+
+@ActiveProfiles( "auth-aware-test")
+public class PatientAppClientSimulationTest extends BaseSuppplementalDataStoreTest {
+
+	/*
+	 * Use Case: share data from other EHRs into the SDS, like the patient app does
+	 */
+
+	@Autowired
+	AppTestMockPrincipalRegistry mockPrincipalRegistry ;
+
+	@Autowired
+	AppTestMockPermissionRegistry mockPermissionRegistry ;
+
+	private static final String FOREIGN_PARTITION_A_NAME = "http://my.ehr.org/fhir/R4/" ;
+	private static final String FOREIGN_PARTITION_OTHER_NAME = "http://community.ehr.net/" ;
+
+	private IIdType authorizedPatientId;
+	private IIdType foreignPatientIdOther;
+
+	private SdsAssertions sdsAssertions ;
+	private PartitionAssertions localPartition ;
+	private PartitionAssertions foreignPartition1 ;
+	private PartitionAssertions foreignPartition2 ;
+
+	private final IdGenerationStrategy testSpecificIdGenerationStrategy = new IdGenerationStrategy() {
+		@Override
+		public IIdType generateId(Class<? extends IBaseResource> resourceType) {
+			return new IdType( resourceType.getClass().getSimpleName(), createTestSpecificId() ) ;
+		}
+	} ;
+
+	@BeforeEach
+	public void setupAuthorizedPatient() {
+		authorizedPatientId = new IdType( FOREIGN_PARTITION_A_NAME, "Patient", createTestSpecificId(), null ) ;
+		String token = mockPrincipalRegistry.register().principal( "FOREIGN_A", authorizedPatientId.toString() ).token() ;
+
+		foreignPatientIdOther = new IdType( FOREIGN_PARTITION_OTHER_NAME, "Patient", createTestSpecificId(), null );
+
+		IGenericClient localClient = authenticatingClient( token ) ;
+		IGenericClient foreignClient1 = authenticatingClientTargetingPartition( token, FOREIGN_PARTITION_A_NAME ) ;
+		IGenericClient foreignClient2 = authenticatingClientTargetingPartition( token, FOREIGN_PARTITION_OTHER_NAME ) ;
+
+		sdsAssertions = new SdsAssertions( localClient ) ;
+		localPartition = sdsAssertions.local() ;
+		foreignPartition1 = sdsAssertions.foreign( foreignClient1, authorizedPatientId ) ;
+		foreignPartition2 = sdsAssertions.foreign( foreignClient2, foreignPatientIdOther ) ;
+		/* always generate a new randomized resource id for resources created in these partitions */
+		foreignPartition1.operations().with( testSpecificIdGenerationStrategy );
+		foreignPartition2.operations().with( testSpecificIdGenerationStrategy ) ;
+	}
+
+	@Test
+	void canShareForeignPartitionForAuthorizedPatient() {
+
+		/* store local patient */
+		localPartition.operations().patient().create() ;
+
+		/* store foreign partition 1 */
+		foreignPartition1.operations().patient().create() ;
+
+		List<Runnable> resourceTasks = partitionResourceCreationTasks( foreignPartition1.operations() ) ;
+		resourceTasks.forEach( Runnable::run ) ;
+
+		foreignPartition1.assertClaimed() ;
+		List<Linkage> linkages = foreignPartition1.linkages().assertPresent() ;
+		assertThat( linkages, hasSize(1) ) ;
+	}
+
+	@Test
+	void canShareForeignPartitionOtherThanForAuthorizedPatient() {
+
+		/* store local patient */
+		localPartition.operations().patient().create() ;
+
+		/* store foreign partition 2 */
+		foreignPartition2.operations().patient().create() ;
+
+		List<Runnable> resourceTasks = partitionResourceCreationTasks( foreignPartition2.operations() ) ;
+		resourceTasks.forEach( Runnable::run ) ;
+		foreignPartition2.assertClaimed() ;
+		List<Linkage> linkages = foreignPartition2.linkages().assertPresent() ;
+		assertThat( linkages, hasSize(1) ) ;
+	}
+
+	private List<Runnable> partitionResourceCreationTasks(SdsPartitionOperations ops) {
+		List<Runnable> resourceTasks = new ArrayList<>() ;
+		for ( int i = 0 ; i < 10 ; ++i ) {
+			resourceTasks.add( () -> {
+				ops.resources( Condition.class ).create( configureCondition() ) ;
+				ops.resources( Observation.class ).create( configureObservation() ) ;
+			});
+		}
+		return resourceTasks ;
+	}
+
+	private BiConsumer<SdsPartitionOperations, Condition> configureCondition() {
+		return (ops, condition) -> {
+			IIdType patientId = ops.id().orElseThrow(AssertionFailedError.class) ;
+			condition.setSubject( new Reference( patientId ) ) ;
+		};
+	}
+
+	private BiConsumer<SdsPartitionOperations,Observation> configureObservation() {
+		return (ops,observation) -> {
+			IIdType patientId = ops.id().orElseThrow(AssertionFailedError.class) ;
+			observation.setSubject( new Reference( patientId ) ) ;
+		};
+	}
+}