Dad knits jumpers for everyone, even GIL and Lifter, and he wants everyone to wear them on their next mission to Venus. But Venus is far too hot for woolly jumpers and Cosmo, Sol, GIL and Lifter find themselves suffering in the heat. When Lifter and GIL shut down, they all roll down a hill, piling up back at the ship. Cosmo takes Sol inside to keep him cool and then makes a plan to prove to Dad that Venus is definitely too hot for jumpers.