How does March foul up Jesse’s plan?

March blows their cover. When the rebels turn on Canning once again, who has finally awoken from his pain-inflicted coma, March can stay hidden no longer. As one rebel raises his gun to shoot Canning in the head, March bursts from his cover in the shadows. Before March has a chance to defend himself, the rebels have leapt upon him and tied him alongside the slaves against a tree.