Justin, Robert and Little Monster are surprised to meet their exciting new neighbour Mac the Explorer.

Robert is being judged for a special robot award, but is too nervous to pass all the tests - so Justin decides to take them for him.

Little Monster blocks the pipes with custard, so Robert calls in the help of slop experts Cook and Line from Swashbuckle.

Justin needs to fix Robert the Robot's memory chips when they accidentally come loose.

Justin is in a singing mood, so Robert uses a new invention to help his friend pick his favourite song.