Show creator Michael Hirst has confirmed Bjorn and Harald (Peter Franzén) are seriously injured in part B but did not disclose whether they would survive.
Ludwig also confirmed he would be returning in part B, but did not specify how long for or in what form.
Hirst hinted to TV Guide: “He’s not dead, is he? He’s very, very badly wounded.
“I can’t tell you too much but what I can tell you is the [midseason premiere] is an extraordinary episode and a number of things that you thought were true at the end of [midseason finale] proved not to be quite true.”
Ludwig added: “Nobody would be expecting that [Bjorn to die], which is why I think it’s a genius move.
“It’s something that I had spoken to [Hirst] about in a lot of ways, and I said that I wanted Bjorn to go at the hands of somebody like Ivar.
“If it wasn’t Ivar, then it would have been by his own hand or something so tragic that the audience was just kind of floored by it.
“Because it’s so obvious for Bjorn to finally come up and achieve all this greatness and take his brother down and save the day, and it’s kind of what everybody secretly wants.
“And that’s kind of what I loved about the choice is that he goes — I’ll tell you this though.
“He doesn’t go without a fight. And whether or not he is still alive, you will see a version of Bjorn is some way, shape, or form.”
Vikings is streaming on Amazon Prime now