transformer - where is the closed path in tesla coil?

I saw a bunch of videos about Tesla coil which works on like an air cored transformer producing high voltage but could be figured it out how exactly it works I mean if we bring a tube light, lamp then it starts glowing without any physical connection. we need a closed path to complete the circuit. my questions are 1.how the power is transferred from the air directly to the load(a blub)? 2.if power is transferred then how it formes a closed path?