He added: “That’s one of the downsides to being in a battle, I think. This can happen too, but all will be revealed.”
Hirst then went on to tease the final series will be seriously emotional and warned fans “if you have tears to shed then be prepared to shed them”.
He added: “The characters who we all, including me, have grown to love with all have their fates decided, whether they live or die is in the hands of the gods, but of course, I had a hand in it too.
“I think the conclusion of the saga is deeply satisfying, a proper and meaningful ending.
“I hope all of our fans will feel the same way. I tried to do justice to all of my characters and I hope I succeeded.”
Vikings is streaming on Amazon Prime now