diff --git a/backend/app/models.py b/backend/app/models.py
index 5887c13..c2a2c4e 100644
--- a/backend/app/models.py
+++ b/backend/app/models.py
@@ -87,6 +87,7 @@ class Dewar(Base):
     dewar_serial_number = relationship("DewarSerialNumber")
     slot = relationship("Slot", back_populates="dewar")
     events = relationship("LogisticsEvent", back_populates="dewar")
+    beamline_location = None
 
     @property
     def number_of_pucks(self) -> int:
diff --git a/backend/app/routers/logistics.py b/backend/app/routers/logistics.py
index ee499e1..5295e22 100644
--- a/backend/app/routers/logistics.py
+++ b/backend/app/routers/logistics.py
@@ -1,4 +1,5 @@
 from fastapi import APIRouter, HTTPException, Depends
+from pydantic import ValidationError
 from sqlalchemy.orm import Session, joinedload
 from typing import List, Optional
 from ..models import Dewar as DewarModel, Slot as SlotModel, LogisticsEvent as LogisticsEventModel
@@ -24,55 +25,46 @@ def calculate_time_until_refill(last_refill: Optional[datetime], refill_interval
     return max(0, int(time_until_next_refill.total_seconds()))
 
 
-@router.post("/dewars/retrieve", response_model=DewarSchema)
-async def retrieve_or_return_dewar(data: LogisticsEventCreate, db: Session = Depends(get_db)):
-    logger.info(f"Received data for retrieve_or_return_dewar: {data}")
-    dewar = db.query(DewarModel).filter(DewarModel.unique_id == data.dewar_qr_code).first()
-    if not dewar:
-        raise HTTPException(status_code=404, detail="Dewar not found")
+@router.post("/dewars/return", response_model=DewarSchema)
+async def return_to_storage(data: LogisticsEventCreate, db: Session = Depends(get_db)):
+    logger.info(f"Returning dewar to storage: {data.dewar_qr_code} at location {data.location_qr_code}")
 
-    # Fetch the associated slot if it exists
-    slot = db.query(SlotModel).filter(SlotModel.qr_code == data.location_qr_code).first()
-    if not slot:
-        raise HTTPException(status_code=404, detail="Slot not found")
+    try:
+        # Log the incoming payload
+        logger.info("Received payload: %s", data.json())
 
-    # Check the last event for this dewar to determine the next action
-    last_event = db.query(LogisticsEventModel).filter(
-        LogisticsEventModel.dewar_id == dewar.id
-    ).order_by(LogisticsEventModel.timestamp.desc()).first()
+        dewar = db.query(DewarModel).filter(DewarModel.unique_id == data.dewar_qr_code).first()
+        if not dewar:
+            logger.error(f"Dewar not found for unique ID: {data.dewar_qr_code}")
+            raise HTTPException(status_code=404, detail="Dewar not found")
 
-    if last_event and last_event.event_type == "retrieved":
-        # Create a 'returned' event if the last event was 'retrieved'
-        new_event = LogisticsEventModel(
-            dewar_id=dewar.id,
-            slot_id=slot.id,
-            event_type="returned",
-            timestamp=datetime.now(),
-        )
-        dewar.last_retrieved_timestamp = None
+        slot = db.query(SlotModel).filter(SlotModel.qr_code == data.location_qr_code).first()
+        if not slot:
+            logger.error(f"Slot not found for QR code: {data.location_qr_code}")
+            raise HTTPException(status_code=404, detail="Slot not found")
 
-        # Update the location to the slot
+        if slot.occupied and slot.dewar_unique_id != data.dewar_qr_code:
+            logger.error(f"Slot {data.location_qr_code} is already occupied by another dewar")
+            raise HTTPException(status_code=400, detail="Selected slot is already occupied by another dewar")
+
+        # Update slot with dewar information
         slot.dewar_unique_id = dewar.unique_id
         slot.occupied = True
+        dewar.last_retrieved_timestamp = None
+
+        # Log the event
+        log_event(db, dewar.id, slot.id, "returned")
         db.commit()
-        logger.info(f"Dewar {dewar.unique_id} returned to slot {slot.qr_code} successfully.")
-    else:
-        # Create a 'retrieved' event
-        new_event = LogisticsEventModel(
-            dewar_id=dewar.id,
-            slot_id=None,
-            event_type="retrieved",
-            timestamp=datetime.now(),
-        )
-        dewar.last_retrieved_timestamp = new_event.timestamp.isoformat()
-        logger.info(f"Dewar {dewar.unique_id} retrieved successfully.")
-
-    db.add(new_event)
-    db.commit()
-    db.refresh(dewar)
-
-    return dewar
 
+        logger.info(f"Dewar {data.dewar_qr_code} successfully returned to storage slot {slot.qr_code}.")
+        db.refresh(dewar)
+        return dewar
+    except ValidationError as e:
+        logger.error(f"Validation error: {e.json()}")
+        raise HTTPException(status_code=400, detail="Invalid payload")
+    except Exception as e:
+        logger.error(f"Unexpected error: {str(e)}")
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 @router.post("/dewar/scan", response_model=dict)
 async def scan_dewar(event_data: LogisticsEventCreate, db: Session = Depends(get_db)):
@@ -109,13 +101,12 @@ async def scan_dewar(event_data: LogisticsEventCreate, db: Session = Depends(get
             logger.error(f"Beamline location not found: {location_qr_code}")
             raise HTTPException(status_code=400, detail="Beamline location not found")
         dewar.beamline_location = location_qr_code
+        logger.info(f"Dewar {dewar_qr_code} assigned to beamline {location_qr_code}")
 
     log_event(db, dewar.id, slot.id if slot else None, transaction_type)
-
     db.commit()
     return {"message": "Status updated successfully"}
 
-
 @router.get("/slots", response_model=List[SlotSchema])
 async def get_all_slots(db: Session = Depends(get_db)):
     slots = db.query(SlotModel).options(joinedload(SlotModel.dewar)).all()