"One more thing...," John said as he reached into his bag, and pulled out a thin strip of magnesium and a lighter. "This is going to be bright," he muttered as he attached the metal to HK.
Turning back to Harper and Tasha, John said, "You guys might want to cover your eyes. Here goes!"
As John lit the magnesium, HK's flamethrower began sparking, before a loud WHUMP of air was released. The robot flew through the air, slamming straight into the center of the large door. The Thermite was quickly ignited by the magnesium, and instantly began burning the door, reaching extremely high temperatures very quickly.
As the flames roared, HK fell back to the ground, a little dented, but no worse for the wear. John grinned. "Knock knock."