Sigma Madelline or Bust

Two of the bodies were dragged from elsewhere, a tiny residue on the floor in the quarters showing from where.

Bentom's care is meticulous and thorough. Once in the infirmary, he quickly ascertains that the bodies were killed by a sharp cutting instrument, deep enough and with enough force that ribs were scored and cracked by the impact, then they bled out. One of them was struck from behind, split open from shoulder to hip in a cross cut. Likely a right handed assailant wielding the long instrument with two hands, or they're very strong.

What would you like to do next? The ship is devoid of any other humans.

Reminder for the autopsy...

With the exception of the three bodies, the entire crew is missing. The woman from the footage is unidentified, but definitely not a member of the expedition to this system, be it from the science vessels, the cargo ship, or the station itself.

The bridge...

The bridge is busted open, the door looks like it was cut apart with a welder. Inside, you see no signs of life, at least to the casual eye.

The bridge is deserted, the displays in low power mode. The lights stubbornly remain dim, as if in night watch mode. A comm terminal to your right flashes red and then with a burst of static, sparks flash from the sides as it dies.

When you step in, the ground crunches beneath your boots. A brown crust of some material flakes and powderizes beneath your tread.

There is no one on the bridge that you can see, alive or dead.

Bentom will be able to tell that it is blood, or was. Freeze dried to terrific cold, then warmed, it cracks to a powder as soon as it's touched.

There are no hull breaches, visible or otherwise, and no gathered atmo near the ship, so it wasn't vented.

The logs show that someone turned off the environmental controls and actively radiated heat, so that the whole ship north of engineering dropped to super freezing over the course of a week.

If I recall correctly, the proper codes have been entered into the computer core giving all of you unrestricted access to the ships systems. With that access, you could certainly do the same thing, but without total access, the safety protocols would stop you.

Tracing the access logs, you see that the commands were given from engineering, likely after the crew had holed up in there. The engineering section (and also the crew quarters) were exempted from shutting off the heat control systems of the STS Tranquility and so would have been, for that week, the only place on the ship habitable.