I was in Blighttown for a couple of hours yesterday and decided to head back out in the end. It's a good place to farm souls but I didn't have anything to cure toxins, which was proving annoying as I was getting hit quite often by the blowdart snipers. Decided to head back out and over to Darkroot Gardens to try and farm some Blooming Purple Moss which can cure toxins, then head back down. Went down to Darkroot Basin instead, killed all of the Silver Golem dudes, then went after the Hydra. Didn't spot there was a drop in the water, and fell to my death, leaving 7k souls behind. Need to try and get them back tonight if I can, as I've not lost more than 5k souls in any one go as a result of dying, and I'd like to keep it that way. I was kicking the Hydra's ass as well :/