I really enjoyed this one - great premise, lovely characters and a wonderful story. 5 stars for keeping me turning the pages.The main character is Wren - she is a 17 year old reboot. A reboot is someone who has died due to KDF - a virus that allows the dead to come back to life....sort of. Each person is different and it is thought that the longer it takes for someone to come back, the better they will be as a reboot because they have less emotion and are tougher fighters. A reboot can't really be killed in a normal way either. They heal from gun shot wounds and broken bones in minutes. Wren happens to be a reboot who was dead the longest - 178 minutes. Very early on we are also introduced to a newbie - Callum 22. He was dead for 22 minutes and in the reboot world, he is considered too human still. He moves slowly, still has feelings and isn't very tough. As a matter of fact, any reboot under 60 is typically seen as a liability. It is Wren's job to train newbies - typically she chooses the highest numbered one but she has made the decision to take on Callum and it changes her world completely. It is implied throughout the story that because she was dead for so long, that Wren doesn't have feelings. This couldn't be further from the truth. One of the things I loved about this story was seeing the change in the character. Wren spent 5 years thinking she was this unfeeling shell and to take Callum's words, a monster, because that is what the humans and HARC made her feel. With the introduction of Callum, he forces her to see that she does have feelings and even though she isn't necessarily human anymore, she is still more than just a tool the HARC uses to keep people in line.I really enjoyed how the relationship was built between Wren and Callum as well. There were definitely the ups and downs in the beginning - Callum made Wren face things she didn't necessarily want to and she had to get him ready for missions but they eventually came to see that they needed each other. The secondary characters were done well too - Ever, Addie, Leb, Tony and Desmond. All were integral to the story and I hope we get to see more of them at least those we can in the next book. Well done for a first book in the series and I am really looking forward to book 2 and what happens with the Reboot Reservation.