Mario was panting as he got to the front door of Bowser's castle. The green, red-haired turtle-bull dog hybrid that was Mario's arch nemesis had apparently taken a liking to technology, apparent from the lasers, hovercraft, forcefields, and robots the red-capped plumber was facing more and more frequently. Bowser hadn't given up on the good ol' Goombas, bottomless pits, and Bullet Bills present from the first Super Mario Bros., but from now on Mario would have to worry as much about stun rays as fire poles. It was all a part of who Bowser was. The Koopa longed for power, in whatever form. It was what fueled his two greatest desires, to beat Mario and to marry Princess Peach. Just two signs of strength.
The particular symbol of power Mario was facing at the moment was a red energy field around the large, wooden front double-doors to Bowser's black castle. There was a gold-plated lead 'key' Mario had lugged in from behind the castle, which was essentially a cube with two handles on opposing sides. Mario slid the gilded block into a slot between the two doors designed for it. The red sparks playing around the doors converged onto the block, which allowed one of the doors to open. Mario pushed the door enough so that a sizable crack appeared, and squeezed through.
The first room Mario entered was a large staircase. There were several hazards present on the stairs: there were stun rays, pistons, energy turrets, enemies literally crawling out of the woodwork. It looked like quite an impressive obstacle course, and indeed, it wasn't something Mario could sneeze at. Still, it wasn't something he couldn't handle. Mario leapt into action, springing off Gombas, hopping over Bullet Bills, sprinting past rotating energy turrets. It seemed as though the man had a star inside him, feeding him an unending stream of energy.
As Mario reached the top of the staircase, a second set of double doors opened. Bowser was holding the door, politely ushering Mario inside. Mario instantly leapt back, landing in a crouching position with his fists up. Bowser laughed.
"Please, Mario. I'd like to save the brawl for after big reveal," Bowser stated, "I think Donovan and I have come up with something real special this time, and I'd the opportunity to truly savor this. Then we can go Man to Koopa."