The Game, Series 1, Episode 5, TV review: Clever penultimate instalment leaves us chomping at the bit for next week

*Spoiler warning!* Paul Ritter is so mesmerising as Bobby Waterhouse I was sure he was the bad guy

The Game: Hester Waterhouse (JUDY PARFITT), Bobby waterhouse (PAUL RITTER) (BBC)

Cor blimey, there are more moles in The Game than that time Adrian Mole canoed down the River Mole with a mole. Yes, it’s raining moles at MI5 as this clever penultimate episode of a hugely enjoyable series sucker-punched us with a nifty one two in the closing moments.

Whether you were feeling smug, surprised or disappointed that ‘always the quiet ones’ beardy Alan Montag (Jonathan Aris) was discovered to be the one squawking all sorts of Her Majesty’s intel to the KGB, you’d have to be one clever sausage to have guessed that wife Sarah (Victoria Hamilton) was a Commie-lovin’ traitor too.

So it turns out that it’s Mr and Mrs Montag (that German surname should have been a giveaway!) who are the double agents. Cut them and they bleed Red Army. As Joe (Tom Hughes) ran the rule over the prime suspects, from grizzled MI5 stalwart Daddy (Brian Cox) to flibbertigibbet newcomer Wendy (Chloe Pirrie), suspicion fell in turn on each of his colleagues. ‘Betrayal must be heartbreaking and exhausting’ Alan had told Daddy. ‘And those that do it think they’re being ever so brave’. But it wasn’t himself he was speaking of but Sarah, who we must assume dragged the harmless sap into it in the first place.

Of course, the big question was – why? Why, Alan?! What’s so great about Russia anyway? His stock, and somewhat clichéd answer – 'Do you have something you believe so passionately it goes beyond simply loyalty that it lives in your blood, your heart, your bones?’ – was frustratingly vague at first. Once we saw Sarah fraternise with the sinister Odin (Jevgenij Sitochin) the full weight of his words came home. It isn’t Mother Russia that he’s willing to commit treason for, it’s Sarah. Oh Alan, you big traitorous romantic you!

In all honesty I’d had the twitchy Bobby Waterhouse down as the inside man, mainly because Paul Ritter’s performance is so mesmerising that it seemed too good to waste on one of the good guys. But, no, the only Mother he serves is his own. And she’s far more brutal than anything the KGB can offer. While I’m a tiny bit disappointed – I was so looking forward to Bobby’s ‘Yes, it was me! Haha!’ speech – I’m delighted that we’ll have more of Bobby and his Mother to look forward to in future series (hint hint, BBC). Bowler hats doffed deferentially to the wonderful Ritter and Judy Parfitt as Britain’s most terrifying mum.

Next week’s finale promises to be a cracker and I look forward to seeing the inevitable showdown between catwalk model Joe and waxwork model Odin. My heart bleeds though for poor Alan. ‘I’d do anything to keep you’ he told Sarah. Turns out he really means it too. I’ll be sad to see the back of the Fray and its brown wallpaper - bravo to Toby Whithouse and his ‘Hoover salesmen’.