In the novel, Deputy Keith Clayton drowns while he's trying to save his son, Ben.
In Chapter 36, Keith confronts Beth about Logan Thibault. At this point, Keith is jealous about Logan's visibility in Ben's life, and he's also not too thrilled about Logan's involvement with Beth. As Keith tries to intimidate Beth into getting back together with him, Ben bursts in on them. Frightened about the possibility of losing his mom, Ben yells out that he won't be made to live with his father, Keith. Not long after his outburst, Ben rushes out of the house.
In Chapter 37, both Beth and Keith eventually realize that they have to find Ben before the flooding gets worse. By this time, the rainstorm is at the height of its power. Meanwhile, Beth thinks that Ben might be at the tree-house, so she and Keith make their way laboriously through the forest.
In Chapter 38, they struggle through the mud and attempt to reach the tree-house, which is situated near the dangerously swelling creek. By the time they reach the tree-house, the creek waters are close to overwhelming the rope bridge, which leads to the tree-house platform. Soon, they see Ben barely hanging on to one end of the rope bridge.
Keith tells Beth to stay put and tries to reach Ben from the other side. He climbs the tree ladder and tries to make his way across the bridge, only to crash through the tree-house platform into the water. At this point, Keith knows that he's broken some ribs. He battles valiantly to hang onto part of the rope from the bridge, but it's clear that the heaving currents will soon overpower him.
In the meantime, Logan has managed to swim towards Ben, but he ends up colliding with the submerged central landing of the bridge and eventually slamming into Keith. Both men struggle in the water; in a panic, Keith tries to grab onto Logan, so that he can reach above water. In the midst of the struggle, the ropes to the central landing finally break, and the men are left to tussle in the swirling creek. Although the author doesn't explicitly state it, Keith eventually drowns. Ben, on the other hand, is saved by Zeus; he emerges on the other side of the creek holding on to Zeus as they swim away from the tree-house and rope bridge.
In the epilogue, Beth puts flowers on Drake's grave and also, on Keith Clayton's grave. It is Keith's birthday, and Beth is laying a large floral arrangement on his grave. She wants to remember him for dying in the act of saving Ben and for carrying her when she fell on the day of the storm. The story ends with Beth and Ben returning home to Logan.