Nappa...the Invincible?

Nappa's power builds up and he sets his sights on Tien. A sneak attack by Chiaotzu seems to give the Earth's Special Forces the upper hand but at what cost? Unscathed, Nappa emerges from the blast. Chiaotzu has given his life in vain and failed to help Tien. Piccolo plans a new attack, but will it work?