I'm SO intensely annoyed by this episode! I'm glad that I'm not alone in this regard!
The number of people Layton has personally killed (and eaten, back in the day) - to not simply stab Wilfred when he was alone, unarmed, and surrounded... the mind boggles! As some have pointed out, Wilfred had useful knowledge of the train - but so does Melanie's daughter Alek. Between them, the rest of the engineers would have managed fine. AND - by not killing Wilfred, they directly killed Melanie - because if Wilfred had died right then, Snowpiercer would have managed to pick her up as planned!
This is just the stupidest plot hole, terrible writing on a show that otherwise has made good sense - it's almost like this episode was written by someone else.
There was ample opportunity to kill or at least beat up and detain Wilfred, and absolutely no downside. They've been at war with HIM - not the starving people he rules over with an iron fist! The second Wilfred was announced dead, his grip of fear over everyone on Big Alice would be loosened. There's more than enough of them to convince Wilfred's supporters on Snowpiercer that he was an evil bastard. And if not, who cares? Layton and co still control the train, hospitality is on their side, and the tail - who still comprise the only significant force of warriors on the train. No-one is going to fight for a dead Wilfred, and if that was such a major concern, they could have suggested that he gave his life heroically in fixing the train, and died a saviour to all.
He's still gone! And no problems now, with collecting Melanie, reuniting her with her daughter and fella... happy days!
This was just a writer so stuck and so lazy that they couldn't even answer the question themselves - so they didn't bother writing or filming a scene, we just suddenly see Layton in handcuffs!?!?! Bizarre. I haven't yelled at the TV in pure annoyance for ages 😉
