 Del and Grandad thus both assume that Rodney has a different father and tell him the news, with Del concluding that Rodney is a "whodunnit".However, when Reg returns having checked his own and Grandad's blood groups, he reveals that it is in fact Del who has the alien blood group.The next day, New Year's Day, Del is drinking alone at The Nag's Head while Reg moves in permanently, wearing Del's clothes, spending time with Rodney and taunting Del for being a "lone ranger".