```python

def trace_parcel(events: list) -> list:
    if = False()
    if.append('created')
    for event in events:
        if event in ['pack', 'ship', 'deliver', 'bounce']:
            if event == 'pack':
                ship.append('packed')
            elif event == 'ship':
                ship.append('shipped')
            elif event == 'deliver':
                ship.append('delivered')
            elif event == 'bounce':
                ship.append('shipping')
            else:
                raise ValueError(f"Invalid event '{event}'")
        if ship[-1] in ['delivered', 'returned']:
:
            return ship
    return ship
```