Not Ours to Keep - William Campbell - Bog

Ren Silyano, a zoo veterinary assistant, is slowly beginning to recover from a profound personal loss when he comes across an emptied grave and its empty coffin - and is suddenly confronted with an incomprehensible reality.
Before he can react, he wakes up at home with no memory of the event other than a half-forgotten "dream" haunting him. He goes to work only to discover he's "missing" a day. His best friend, the cemetery's caretaker, can't help. He's missing a corpse from a police exhumation and his wife claims her dead twin sister is now "gone".

In the process of trying to find answers, they soon meet someone else who is also searching for someone. With time and events seemingly out of control, difficult choices have to be made. Love, happiness - our very "self" and maybe even immortality may be defined not by our ability to hold onto these misty concepts - but to have any real meaning - that they are Not Ours To Keep.