Futurity. Memorabilia Trilogy, #3

Sean is back on the Philly police force trying to forget about the man he killed. His name was Sands and he deserved it, but his daughter didn't see it that way. She wants to make Sean pay. Harper is Sean's ally from a dystopian future. She must find the missing photographic evidence of time travel that Sands took and needs Sean's help. As they follow the years-old leads, they receive an anonymous ransom demand; someone wants to trade the photographs for a large sum of money.
The only catch is it has to be delivered by the person who killed Sands. The sins of Sean's past may come back to haunt him in a strange and unfamiliar future.