!! Spoilers for series six, episode five of Slow Horses. Nothing beyond this episode. Only read on if you've seen it!

In this penultimate episode of the series, we're no longer looking for answers to the big mysteries. Lamb has figured it out. We get to see him taking control of the situation: telling Taverner what's going on and filling in the gaps for her; putting in some real spycraft to follow the Russian woman; and remotely directing Ho on what to investigate and how to piece together the final details.

We need to see moments like this from Lamb, otherwise you're just watching a rather unpleasant man and a terrible, terrible boss going through life. He redeems himself by being incredibly smart when it matters and sniffing out what's really going on. Everything else is forgiven when he's also saving the day.

By contrast, River is such an earnest and lovable character, and yet he's consistently rubbish. We open the episode with him trying to get a civilian to part with her car - turns out it's not as easy as it looks in the movies. And when he eventually gets behind the wheel, he has an unexpected canine passenger along for the ride. Typical River. Later on, when he and Sid are trying to escape the airfield, he drives them round and round in circles until finally figuring it out. And when he does ultimately give himself up so Sid can get away, it's not so much bravery as just hoping that he'll get a date out of it afterwards. Lovable, loyal, slightly useless.

River and Sid's relationship develops significantly in this episode. River gives Lamb an update of his situation, and Lamb says: "Sid Baker? She died the last time she was with you, didn't she?" which sums up where River and Sid were at before this drama started. Now, they sit under a tree, chatting and bonding, waiting for backup after finally getting the better of the Russian hit squad. What really warmed and then broke my heart was at the airfield. After hearing that River missed a light being left on for him at his late grandfather's house, Sid says she would leave a light on for him. Such a cute scene given she was about to be sacrificed to the Russians.

Taverner continues to make bad decisions, but also it seems less nefarious at this point. Rather than being a double agent or anything like that, we now know she's compromised and just scrabbling to get out of it. Despite taking some wrong turns, I still thought her speech at the oversight committee was great: "You shouldn't be asking me how I funded this. You should be asking me how I will fund the next one. And the next one after that." It's so easy to judge Taverner, but the amount of bureaucracy she has to put up with whilst trying to keep the country safe is unimaginable.

So, with the mystery all but revealed, our attention switches from searching for answers to wondering how our characters are going to get out of their various situations. River giving himself up to the Park, whilst Sid is on the run. Harkness and his gang are on the way to the safe house, which now contains Ho, Flyte and Reece, along with the original four: Standish trying to be useful, Moira cooking for everyone, Shirley (still alive!) making petrol bombs (love that that's her natural instinct for an activity), and Louisa being grumpy about being dragged back into this world.

We've got one more episode to tie up these loose ends and see who does manage to survive to be in series seven.