You were on a mission. You’d been told to head to the extraction point immediately-

Everyone was there but you. Ghost was beginning to worry-

And so he whistled. It was short- but it had a rhythm to it.

When the two of you were younger, you’d come up with a way to communicate, and you’d landed on whistling

So whenever one of you needed the other, you would whistle..

And pray to god the other whistled back