Following the loss of his girlfriend, Celine, in a Paris subway attack that also leaves him severely injured, Robert, the main character in my novel, "Title X" travels across Europe seeking her killer but ultimately finds peace within himself. His journey begins as a sojourn of escape from his grief but quickly devolves into a spiraling addiction as he comes to terms with his loss, his own injuries, and the startling truth about the killer’s identity. His addiction starts naively, becomes insidiously macabre, but eventually leads him to his final redemption.
The path starts as Robert returns to the scene of the attack. It follows his mourning perambulations across the Continent, through to his discovery of the killer and arrives at the revelation that he himself is to blame. Robert learns that the route to the truth is not found in one of Europe’s back alleys, but within his own conscience. Through a painting she leaves behind, Celine transcends her own mortality to guide Robert towards the astonishing truth that challenges his own beliefs about himself and the events leading
to the attack.
Robert, mourning Celine, journeys across Europe only to find he was to blame for her death.
That's not a novel, it's a French film. Zut alors.
You need some specifics here and a sense of urgency. Strike up a Gitane, pour some wine; start again.