Kryten has a mid-life crisis as he is half-way through his life cycle and consoles himself with a new crimson shell complete with sub-woofers. To cheer him up the crew decides to introduce him to Butler, a supposedly less intelligent mech but he is extremely sophisticated, making Kryten feel worse. Salvation arrives when Kryten realizes that the very universe itself is also subject to a mid-life crisis and he can help it.
—don @ minifie-1