diff --git a/usr/local/bin/torrent-mover b/usr/local/bin/torrent-mover
index 968f6e3..503f426 100755
--- a/usr/local/bin/torrent-mover
+++ b/usr/local/bin/torrent-mover
@@ -1,5 +1,32 @@
 #!/bin/bash
-# Torrent Mover v5.1 - Numeric Handling Fix
+# Torrent Mover v5.3 - Singleton Implementation
+
+# Singleton pattern
+LOCK_FILE="/var/lock/torrent-mover.lock"
+MAX_AGE=300  # 5 minutes in seconds
+
+# Check for existing lock
+if [ -f "${LOCK_FILE}" ]; then
+    PID=$(cat "${LOCK_FILE}")
+    
+    # Check if process exists
+    if ps -p "${PID}" > /dev/null 2>&1; then
+        echo "Already running (PID: ${PID}), exiting."
+        exit 1
+    else
+        # Check lock file age
+        if [ $(($(date +%s) - $(date -r "${LOCK_FILE}" +%s))) -lt ${MAX_AGE} ]; then
+            echo "Recent crash detected, waiting..."
+            exit 1
+        fi
+        echo "Removing stale lock (PID: ${PID})"
+        rm -f "${LOCK_FILE}"
+    fi
+fi
+
+# Create new lock
+echo $$ > "${LOCK_FILE}"
+trap 'rm -f "${LOCK_FILE}"' EXIT TERM INT
 
 set -o errexit
 set -o nounset