Your Robot has finished the cleaning process but cannot find the base station.
When the cleaning process was not started from the base (either due to Spot cleaning or being in a room where the robot has no visible contact with the base station), the robot will return to the original spot where the cleaning process was started.
To recharge the robot, please:
1. Place the robot back at the base station
2. Make sure that it is connected to the base station and let the battery re-charge.
If the recommendations above do not help, please check the article "Please clear path."