I was right – there was very little else to do. I had to assemble the parts of a Big Daddy for reasons I can’t really say, and then with the help of a Little Sister I made it into a museum, where Fontaine was waiting for me. Well, once I’d got through the museum, anyway.
Unfortunately, the museum was pretty much an escort mission, which I hate. You have to stop a Little Sister from being killed as she leads you round the museum and through doors only they can open. Thankfully, I could scout ahead and hack some cameras and turrets to be on my side, helping when the splicers attacked. Amazingly, my third (and last possible) photo of the final camera in the game was just enough to get the maximum research for them, and thus the achievement for “PhD Research”.
Once through the museum, it was the final showdown with a spliced up Fontaine. A very easy to kill spliced up Fontaine at that. It was soon over, and I’d only used one first aid kit and barely half a “tank” of Eve.
So, that’s it. I am tempted to go back round Rapture with an earlier save to get the achievements for Jackpot and Weapons Specialist, though.