Stringfellow Hawke lives alone — except that he doesn't, quite. Tet, his shaggy, unhurried hound, holds permanent station at the lakeside cabin: greeting the float plane, auditing every visitor, and monitoring the grill with a professional's focus whenever Dominic Santini cooks for three and feeds most of it to the dog.
His name carries the series' quiet weight: Tet — an echo of the offensive that defined the war Hawke never left behind. It is exactly the kind of joke Hawke would make: name the one soul you talk to after the thing you cannot talk about.
The pilot gives Tet his defining scene partner-swap: while Hawke is off stealing back a supercopter, the F.I.R.M. quietly installs a white-clad agent at the cabin as a 'housesitter' — whom Dom finds Tet shamelessly charming. Asked whether the dog will be alright alone, Hawke's answer stands for the whole character: Tet takes care of himself.