HP Spectre X360 started smoking

Laptop: 15in HP Spectre X360 CH011DX

I smelled burned plastic and a few moments later smoke came from the left fan vent.

The laptop didn't turn off. I had to shut it down.

I removed the back cover and couldn't find any evidence of burns. No obvious damage to boards or anything.

The battery does seem somewhat swollen but it's not bad enough to be 100% sure.

I removed the battery. The laptop turned on without issue with the ac adapter plugged in.

The laptop won't turn on with the battery and ac adapter pulled in.

The only other issue is that my left vent fan is running at over 6000rpm. The right fan is running at 72pm. This may be due to removing the battery though...