We've become used to the pattern of this sitcom now - a lot of sitting around in a suburban living room and arguing, with our hero, Simon, generally the odd one out. And when it works, it works superbly. The rhythms of the dialogue are beautifully realised. But tonight things kick up a gear. Simon has been on a self-help course that has convinced him he needs to settle old family scores, do some "letting go of the past and healing the moment". The good news is, that makes him much more patient with everyone. The bad news is, he has invited his estranged father round - guest star Allan Corduner. It makes for some brilliantly desperate scenes.