Lockdown (Liars #4)

ARMED MERCENARIES invade a hospital and start taking hostages. Some school students barricade themselves in a surgical theatre. But the mercenaries are HUNTING an injured man ... and he's in there with them. Jarli, creator of the Truth app, is one of the students TRAPPED in the hospital. All the phones are jammed. The building is locked down. No help is coming. The mercenaries work for Viper, a ruthless and deadly criminal. Jarli and his friends have outwitted Viper before-can they do it again? The TRUTH is deadly ...