 As Helen has (conveniently?) booked a week in Cornwall a week before Gordon s leave, he s even more focused on the job, notably energy conservation week, producing a mountain of forms to be filled in (five page) at every use of electric equipment. Colin build a complete methane digestion system for human bio-waste. Gavin s fiancée Jenny turns up after five years abroad, and has amnesia. His gay colleague, house-mate and partner Tim goes trough hell while Mr.Brittas champions the welcome committee. When Gavin tells she was in psychiatric therapy for years after her parents  traumatic accident which turned her into a pyromaniac, Laura realizes the importance of Linda s discovery that Jenny s suitcases contain fuel and lighters. Then Colin reports she s in the basement, admiring his methane experiment; she may not be angered but Gordon is there too...