His baby brother had been wild as a winter storm since he learned Robb was riding off to war, weeping and angry by turns. He'd refused to eat, cried and screamed for most of a night, even punched Old Nan when she tried to sing him to sleep, and the next day he'd vanished. Robb had set half the castle searching for him, and when at last they'd found him down in the crypts, Rickon had slashed at them with a rusted iron sword he'd snatched from a dead king's hand, and Shaggydog had come slavering out of the darkness like a green-eyed demon. The wolf was near as wild as Rickon; he'd bitten Gage on the arm and torn a chunk of flesh from Mikken's thigh. It had taken Robb himself and Grey Wind to bring him to bay. Farlen had the black wolf chained up in the kennels now, and Rickon cried all the more for being without him.
Maester Luwin counseled Robb to remain at Winterfell, and Bran pleaded with him too, for his own sake as much as Rickon's, but his brother only shook his head stubbornly and said, "I don't want to go. I have to."
It was only half a lie. Someone had to go, to hold the Neck and help the Tullys against the Lannisters, Bran could understand that, but it did not have to be Robb. His brother might have given the command to Hal Mollen or Theon Greyjoy, or to one of his lords bannermen.