He instinctively shoots a bolt of electricity when he sees movement, but it shoots off beyond Ivar and hits a tree. Jack's back hits the ground a second later and he lets out a cry of pain, struggling to get free without enough sense to figure out a plan. At least the impact comes with another shock of electricity from his chest.

It only lasts a second though, before his focus shifts to trying to lift his right arm up and hit Ivar's head. If he can't get free that way he can try electrocuting him, although he'll hurt himself in the process.