So while I was flying, something went wrong with the drone: suddenly it stopped responding to altitude commands and shot straight up at full speed. All I could do was watch the altitude climbing by hundreds of meters on my phone screen. Even hitting 500 meters didn't stop it, even though the settings say it shouldn't go higher than that.
At 1000 meters, the app cheerfully informed me the signal was about to cut out and I should head back. Yeah, right—like I had any control over it.)
I'd already made peace with it, figured the drone was headed to space. But a hundred meters later, the thing came to its senses (probably the battery running low was the trigger), switched to emergency landing mode, and dove down just as aggressively. Once we got to about 30 meters above the ground, everything went back to normal like nothing had happened.
Support told me to calibrate before every flight, and to take it in for warranty if it happens again.

At least I got to see the sun for once. We've had nothing but clouds for days.