Last night I ran this adventure from Dungeon. Here's how they got there.
Saving the Miller/Using blood to create a portal:
The players had just returned from saving a miller from being killed. They had travelled through a portal to stop a vampire who was attempting to travel through time. However, they found out that the vampire was just working for one of their enemies, a warlock of some kind. They fought the warlock (on a different planet, that same warlock had stolen some fish from them, and killed one of their party members before escaping), but the warlock used a blood sacrifice powered portal to escape. The party debated whether or not they should use the blood of one of their enenmies to re-draw and open a portal of their own. The wizard (Aistlin) was reading scrolls trying to learn how to use the power of blood to draw portals that allow them to travel through time and space. One character was told by its god that this was not necessarily a good act. The wizard and thief talked them into it. They used the portal to return to their world, a day earlier, to save the miller. While going through the portal, the wizard heard words of thanks and encouragement from the power that had been tempting him with more power.
Upon returning to their home base, they debriefed. They argued with one of the leaders (the head wizard) as they had on previous occassions. Later Aistlin decided they should go apologize and talk with the head wizard. Aistlin has begun to worry about the power that has been talking to him in the portals. They discussed what they had learned from papers they took from the warlock:
Something about power sources and portals:
- Blood sacrifice
The head wizard let them know that someone had now been attacked in transit, and killed by multiple sword wounds. The cleric admitted that Moradin had been talking to him in the portals, but that he was beginning to wonder if it was really Moradin, or someone appearing as Moradin. The wizard, cleric, and rogue all have spellscars they received on one of the trips through the portals. The cleric now has two (rules: these are the equivalent of boons as defined in the DMG 2).
The head wizard suggest they visit his friends at the White Lotus Academy to continue their research on portals. They could either travel through a portal to there, or take a boat (WLA is outside Phlan in my Faerun). They decided to take the portal, but to be armed and ready for battle as they stepped in.