An archeological site on Earth discovered my severed head in a cave. It was several centuries old, by that point, which would clearly indicate that I had at some point entered a time rift and then died.

[y'know, as you do]

The rest of the crew did want to keep me from dying. They were quite upset by it. Nonetheless, I was the one most capable of successfully investigating the time rift, so I chose to do so regardless. There were numerous other beings trapped inside, so it could not be left alone.