Tim awakens in a place he didn't expect and his first uncertainty is whether the Potters have tired of him. His father claims that they called and told him to take Tim.
At this point one needs to introduce the Dark Man. Tim does not remember when the Dark Man first turned up, but he has been present, in Tim's head, during most of the really bad times in Tim's short life. The Dark Man assures Tim that his father is lying. And that he needs help. Wizard help. Tim calls Kreachur.
Meanwhile Harry sends word to the Aurors that Kreachur has been called and goes with Kreachur to keep an eye on things until the Aurors arrive.
He follows a pizza delivery into the flat and intends to stun Tim's father and rescue Tim, but cannot get a clear shot that won't endanger Tim. When Tim's magic has a breakthrough, and his father hits him, Harry waits no longer and attempts to intervene. The abductor curses Harry (and Harry is fortunate that his opponent has bought into the myth that Harry is immune to AK or he would be dead), Tim manages to get away, and Harry kills the attacker before passing out.
The Aurors turn up, Ginny in their wake, and we all adjourn to St Mungo's. There will be an inquiry, Harry is not conscious for it. The Dark Man briefs Tim on what to tell the Aurors.
When he finally regains consciousness Harry is given a talking to by his boss, the head of the DMLE.