From A Wiki of Ice and Fire
|Book(s)|| A Storm of Swords (mentioned)|
A Feast for Crows (mentioned)
Appearance & Character
A Storm of Swords
Dennis and his brothers Ser Peter and Ser Harwyn Plumm are among the men who are sent by Lord Tywin Lannister to the Riverlands in search of his son, after Ser Jaime Lannister has been released from Riverrun by Lady Catelyn Stark.