Session log entry (I'll order the entries later in a format where you can follow the whole story)
Spoiler alert! This log contains Ptolus spoilers, even if the storyline isn't identical to written adventures.
Background: Heroes of Reilukerho witnessed a conflict between Balcazar's vampire allies and Ennin in the harbor area, and then engaged Vampires and their Sauhagin allies. The party had retreated to rest after the fight, which allowed residing Pactlords to move to a safer location now that they had been discovered. What players didn't know was that the pactlords had obtained the Black Grail, and had turned 3 high members of the Lothian church into their evil servants. Fourth one had turned evil, but escaped the mental enslavement and left the path of Lothian.
So, heroes examine the caves and most they find is a letter hinting about the Emperor soon being in their power. Heroes move to Lothian's cathedral (of st. Valien) but aren't let in immediately. Finally they rush in and intervene an Aboleth and a beholder (Eye in the deep) and evil priests and finally defeat them. Also a mind flayer is present, but after his initial mind blast he leaves to take the Grail to safety. Heroes find hints that lead them to another church and it's belltower, where they are attacked by (the fifth) betrayer priest and his minions, and discover a portal to the plane of Quaan.
On their way, two of the heroes spot the fourth priest and get some information from him about the pactlords, the grail and Quaan.
Sorry for poor quality photos! In later games, an actual camera was used instead of mobile phone camera, which works so much better in dim lighting.