Ami lifted the flap.

A heavy, flexible thing, the flap was securely fastened at the top, but Ami was able to raise it nearly vertical. The space inside seemed both wide and deserted, although it was rather dark. Dropping to her knees, she thrust her head and shoulders inside for a better look. Whack ! The flexible flap struck her bent-over buttocks a stinging blow. " Whah ! " Ami yelped, although the accident shouldn't really have surprised her. What was surprising was when the flap rose, and fell harder a second time, this time curving around to deliver most of the **** to the junction of the trapped girl's buttocks and thighs. The spasming of her legs pressed her hips against the top of the opening. Ami was fairly sure she could fit inside by belly crawling, but her present plight made that difficult.