nor might they henceforth have games together , which they had hitherto held , turn and turn about ; in which games was arnkel the strongest , but that man was the best to set against him , and the next strongest , who was called freystein rascal , and was the foster-son of thorbrand , and his adopted son ; for it was the talk of most men that his own son he was , but that his mother was a bondmaid .