Be was the missing puzzle piece. This mission couldn't be done without him and he knew that so why the hell did he disappear last night. You knew it was of his own doing because he left a note specifically for you. On the note he stated over and over how he just needed a break.

His note also led you into the forest a day before the mission was supposed to launch. Just as encrypted in the note you stumbled on a broken down cabin with the flame of a lit candle shining through the window.