Why did Jon lose his connection with Ghost , and will that have any significance in the next book ?
A Storm of Swords - Samwell IV
"That's only Ser Alliser," said Sam. "Everyone knows the sort of man he is." With his noble birth, his knighthood, and his long years in the Watch, Ser Alliser Thorne might have been a strong challenger for the Lord Commander's title, but almost all the men he'd trained during his years as master-at-arms despised him. His name had been offered, of course, but after running a weak sixth on the first day and actually losing votes on the second, Thorne had withdrawn to support Lord Janos Slynt.
"What everyone knows is that Ser Alliser is a knight from a noble line, and trueborn, while I'm the bastard who killed Qhorin Halfhand and bedded with a spearwife. The warg, I've heard them call me. How can I be a warg without a wolf, I ask you?" His mouth twisted. "I don't even dream of Ghost anymore. All my dreams are of the crypts, of the stone kings on their thrones. Sometimes I hear Robb's voice, and my father's, as if they were at a feast. But there's a wall between us, and I know that no place has been set for me."
The living have no place at the feasts of the dead. It tore the heart from Sam to hold his silence then. Bran's not dead, Jon, he wanted to stay. He's with friends, and they're going north on a giant elk to find a three-eyed crow in the depths of the haunted forest. It sounded so mad that there were times Sam Tarly thought he must have dreamt it all, conjured it whole from fever and fear and hunger . . . but he would have blurted it out anyway, if he had not given his word.