Game Of Thrones: 10 Storylines From The Books The Show Ignored
5. Davos Seaworth And The Heir Of Winterfell
In the books, Davos Seaworth doesn't stay a guest of Castle Black for long. After Stannis smashes the wildling army, the King sends Davos south of the Wall to rally the northern lords to his cause. The most notable support he seeks is that of Lord Wyman Manderly of White Harbour.
The Onion Knight meets with Lord Wyman, however since the Lannisters hold Manderly's son hostage he cannot risk open rebellion against Tommen. Instead he opts to remove Davos' head and shortened hand to display them above the gates of White Harbour. A proud token of his fealty to the throne. This is the story he feeds to Lannisters, anyway.
It is actually the head and hand of a common thief (minus the ends of his fingers) dipped in tar above the gates, as a deception to make sure Wylis stays alive. The northern lord then sends Davos on a secret mission - bring Rickon Stark home.
The Manderlys and Glovers learn that the heir to Winterfell is not dead by way of Wex, one of Theon Greyjoy's men when he took the castle. If Rickon were to return to the north, all of those that have joined the Boltons would soon disperse and rally behind the Stark. If Wex's information is correct, Davos must head to Skagos, the island of cannibals, to retrieve Eddard's son.