The last one standing (Paperback)

Five teenage girls named Chloe, Sarah, Liz, Hayley, and Sage decide to get together to form a secret undercover detective team. However, when they decide to do a case over a serial killer, things turn more serious and each of them go missing one by one. The last one standing (the last one to go missing) must find out who the killer is and where her friends are before time runs out and she's next.