Right, so I'm not sure if anyone has encountered this before, but I was exploring Dernholm when out of nowhere, an elite bowguard attacks me unprovoked and manages to murder Virgil.
I decided to hit the quickload key (I had quicksaved just a few minutes earlier) when something even stranger occurs... the game loads and I find myself suddenly standing in a green field, naked, with my companion. There is a chest in the middle of the field which is full of items (they appear to be similar to the character creation shopkeeper items, but I am not certain).
After a baffled moment of laughter, I hit the quickload button again. Nothing happens.

I go to the load menu where I previously had dozens of save games... they're all gone. Every single one of them.

In other words, this is a game breaking bug and I'm no longer laughing.

*sighs deeply*

You're joking i hope...aren't you?

I finished Arcanum two times with the "Official-Final-Patch-State" and 4 times with the "Fan-Patch+High-ressmaps+Virgilmod", never something like this occurred to me and i didn't read about it either...it sounds
more like a virus then a Bug^^.

What Mods do you use?

Aye, I believe that is the root of the problem, I wasn't using any mods. :P

I installed the game fresh from GOG because I was keen to try it and didn't realize that it wasn't already patched.

But I'm not joking, this actually happened... oh, and I also forgot to mention that in the process of teleporting to this mysterious green field of treasure and save game corruption, my character had a sex change too. :'D

Lesson: always check if there is a community patch for the old game you're about to install.

Edit: I only wish I had taken a screenshot of the scenario. It was truly absurd.

This is a rare but not unknown bug. For example, there's a brief discussion of it on Terra Arcanum:

http://www.terra-arcanum.com/phpBB/viewtopic.php?t=1710

And I think there's a thread on it here too but I can't find it right now. In the other cases I've heard of, people were able to reload other saves. I assume you've tried quitting the game, then restarting and loading a different save file? In theory it should only have corrupted that one save file (the quicksave), and the others should be fine. Maybe you couldn't reload from the corrupted save for some reason, but restarting the game will help?

If not, that is truly unfortunate. But if you have to start over, be sure to install the Unofficial Arcanum Patch at least. And remember that much of the joy in Arcanum comes from trying out different characters and roleplaying them differently (making different choices in-game), so on the bright side, you have a chance to do that.

I hope you can recover your saved games, though!

EDIT:
Found the GOG thread on it:

http://www.gog.com/forum/arcanum_of_steamworks_and_magick_obscura/save_game_bug

Not nuch in there, but again, many people have been able to re-load old saves. Try restarting a few times and see if you can get it to work. Just be aware that it may happen again in the unpatched game (by unpatched, I mean without the Unofficial Arcanum Patch).

I would install Drog's UAP, and avoid using quicksave and quickload. For some reason qs and ql often cause problems in these types of games.

Thanks for the replies, people!

It seems I can't recover my save games anymore. I'll take a short break to mourn my character and then restart the game with the unofficial patches and miscellaneous mods installed. I have to say, when browsing the Arcanum forum for bugs, there were some pretty entertaining ones. Almost makes me tempted to play the vanilla version... almost.

Welcome to the strange mysteries of Arcanum.......

It´s sad, but on the other hand, if you choose a lightly different setup, when starting a new game, it shouldn´t be too boring. Arcanum offers many different approaches and it´s all worth the effort.

Not to mention that simply starting with a different name or background (not to mention race or gender) will randomize much of the loot you find.