In the future war against the machines, humans might have gained a brief respite by powering through the flowing rivers where electronic killer robots cannot tread. These bridge-building quadrotors have now closed off that avenue of escape.
The pair of drones you can see in the video use a spool of rope - about 120m between the two of them -- to construct a rope bridge across a seven-metre gap, capable of supporting a human. The drones were able to scan the gap, work out the structure, and do their weird robo-rope-dance all without any human intervention.
Sure, it requires the perfect anchor at either end (and some very complicated programming), but more than anything else, it's an impressive demonstration of the kinds of complex structures two drones can weave, knot and braid with nothing more than a spool of rope. Yep, we're all doomed.