Try whistling

As Sombra zig-zagged across the sand, something hit her.

D.va whistled to summon Tokki. She whistled, and somehow the mech responded to that from several meters away underwater. Tokki's invincible to digital hacking attempts; anyone who's done hacking knows that. But if it responds to sound, then there's the possibility of analog hacking.

Then, something else hit her: a stray cannonblast. The hoverbike careened out of control, forcing her to skid to a stop. D.va, standing smugly where the beach met the asphalt, put two fingers in her mouth and whistled again. The flying mech immediately stopped its **** and flew directly towards her. The pilot, both hands over her perky tits, started walking up to the mech as it landed, her face the picture of smugness.

Sombra worked fast. There was a bluetooth boombox on the sand, abandoned when the civilians fled the scene; Sombra tore through its security like paper. She pulled the audio of D.va's first whistle from the cached stream, frantically slicing it out of the feed. She glanced back at the real world. D.va had entered the cockpit. She frantically boosted the volume on the boombox and fed the sound sample in.

The spliced whistle screeched through the boombox at a deafening volume. Nearby windows splintered and cracked. Sombra clutched her head as the sound tore through her ears. But it was working. Tokki had turned, confused towards the boombox. Without the control of its pilot, who was also clutching her head at the head-splitting sound.

She had managed to hack the unhackable, with five minutes left on the clock. The challenge was how to get it to do anything useful.