Adam Smith 
At the End of Your Tether [PDF ebook] 

Set in 1997, troubled teen Ludo Carre is nervous about returning home to be reunited with the one person he made a connection with in his youth. The night before he arrives, he gives her a phone call to ease his nerves. Big laughs and a familiar sort of cadence in Arlo’s voice don’t just instantly calm him down — they make him excited to see her. That excitement only hurts him more when they show up the next day and find out Arlo has been missing…for the last week. Determined to find her, Ludo takes things into his own hands, but the further he gets into his investigation, the more he questions how well everyone on base, in town, and even he himself really knew her. Where is his best friend — and who is she, as well?