diff --git a/poc-memory/src/graph.rs b/poc-memory/src/graph.rs
index 7c9e3f8..163453b 100644
--- a/poc-memory/src/graph.rs
+++ b/poc-memory/src/graph.rs
@@ -607,25 +607,20 @@ pub fn health_report(graph: &Graph, store: &Store) -> String {
 
     // Orphan edges: relations referencing non-existent nodes
     let mut orphan_edges = 0usize;
-    let mut orphan_sources: Vec<String> = Vec::new();
-    let mut orphan_targets: Vec<String> = Vec::new();
+    let mut missing_nodes: HashSet<String> = HashSet::new();
     for rel in &store.relations {
         if rel.deleted { continue; }
         let s_missing = !store.nodes.contains_key(&rel.source_key);
         let t_missing = !store.nodes.contains_key(&rel.target_key);
         if s_missing || t_missing {
             orphan_edges += 1;
-            if s_missing && !orphan_sources.contains(&rel.source_key) {
-                orphan_sources.push(rel.source_key.clone());
-            }
-            if t_missing && !orphan_targets.contains(&rel.target_key) {
-                orphan_targets.push(rel.target_key.clone());
-            }
+            if s_missing { missing_nodes.insert(rel.source_key.clone()); }
+            if t_missing { missing_nodes.insert(rel.target_key.clone()); }
         }
     }
 
     // NodeType breakdown
-    let mut type_counts: std::collections::HashMap<&str, usize> = std::collections::HashMap::new();
+    let mut type_counts: HashMap<&str, usize> = HashMap::new();
     for node in store.nodes.values() {
         let label = match node.node_type {
             crate::store::NodeType::EpisodicSession => "episodic",
@@ -690,18 +685,16 @@ Types: semantic={semantic} episodic={episodic} daily={daily} weekly={weekly} mon
     if orphan_edges == 0 {
         report.push_str("\n\nBroken links: 0");
     } else {
-        let mut all_missing: Vec<String> = orphan_sources;
-        all_missing.extend(orphan_targets);
-        all_missing.sort();
-        all_missing.dedup();
         report.push_str(&format!(
             "\n\nBroken links: {} edges reference {} missing nodes",
-            orphan_edges, all_missing.len()));
-        for key in all_missing.iter().take(10) {
+            orphan_edges, missing_nodes.len()));
+        let mut sorted: Vec<_> = missing_nodes.iter().collect();
+        sorted.sort();
+        for key in sorted.iter().take(10) {
             report.push_str(&format!("\n  - {}", key));
         }
-        if all_missing.len() > 10 {
-            report.push_str(&format!("\n  ... and {} more", all_missing.len() - 10));
+        if sorted.len() > 10 {
+            report.push_str(&format!("\n  ... and {} more", sorted.len() - 10));
         }
     }