In fact, unstable relationships are kind of all over the place in this book - Cal and his ex-wife Tabytha, a Republican congressional candidate with a penchant for prescription medication, are not exactly on the friendliest of terms, and things only get more rocky as Cal's story progresses. Furthermore, to call Cal's relationship with his philosophical Romanian therapist, Viorela, "complicated" might be something of an understatement. They make such an odd couple to me.
The central plot of All Her Father's Guns is basically this: Cal has had it with paying so much in alimony to Tabytha, and goes well out of his way to do what he can to cause problems for her in her political campaign; he even has Reid helping him with some of the dirt-digging. He wants to find enough to blackmail Tabytha, but he ends up getting much more than he bargained for, and the truths could potentially ruin both of them. Things take an even more unexpected turn when Cal wrecks his car, sustaining injuries to his brain. It is a pivotal moment, as none of their lives will be the same from then on.