Brice awakes with a headache. Is it a symptom of AMS? We give him the "Tylenol test" and he fails -- the analgesic does not resolve the headache. We delay departure another day. Jianping also seems to be in bad condition. He has little appetite, his lips are black (apparently a sign of AMS) and he's also got a headache. The rest of us feel surprisingly well, though I doubt any of us sleeps much.
Brice and I opt to relax today; the three friends go back into the valley, this time on unloaded bikes. It's morning so the valley is dry.
By the time they arrive back in the afternoon, Gong Jianping is knackered. No appetite. Headache. Exhausted. We set up a tent for him in the lee of a wall outside where there is peace and quiet, and he falls into deep sleep.