Quatermass and the Pit (1958)

S1E11 Bubble Trouble

Hap-Pea and Soap-Pea make the choice to take a boat and head over to Poddle Island. Meanwhile, Black Eyed-Pea and Creep-Pea take advantage of their absence, swiping the boat and bringing it back to Poddington. Once the boat is back but neither Hap-Pea nor Soap-Pea has shown up, the rest of the Peas start to panic and embark on a frantic search for their lost friends.