General Grjötgard and the rest of the gang had successfully scaled the wall and managed to assume the identity of a few of the guards.
Grjötgard knew that the reinforcement to invade the castle wasn't coming, he knew that they meant business and Northumbria wasn't like anything that they had encountered.
They were disciplined and Grjötgard knew even if Tyr was to emerge victorious, it wouldn't be at the cost of losing men.
The weaker they got, the more likely failure looked but Grjötgard knew that their priority was freeing Ragnar.
He made a bet with Bjorn and Grjötgard was ready to gamble on the young man's faith otherwise the smart thing would have been to retreat.
"Bjorn Ragnarsson, you're an impressive warrior," Salgard complimented Tyr's brother.
This was rare for the young man, he only did so with exceptional warriors.