Tienne d'Ambreville's Resurrection - Mark of Amber & Castles & Crusades rpg

 "Tienne d'Ambreville, the most powerful wizard in all Glantri, is missing and presumed dead. There are some who would like to keep it that way. Only by entering the dreams of a dying Immortal can player characters discover the truth."

"Meanwhile, a sinister killer stalks the d'Ambreville family, murdering them one by one. Can the heroes identify the killer and solve the mystery before it's too late?"

 Mark of Amber came out in '96 and it hit the stands in a very big way for us as Mystara players. The history of Mark of Amber goes something like this;""Mark of Amber" (1995), by Aaron Allston, Jeff Grubb, and John D. Rateliff, is the third and final adventure for the AD&D Mystara line. It was published in June 1995." And what set it appart from other Mystara rpg products is the fact in two different directions one the incredibly strong potraits of the  d'Ambreville family, & two it's the direct sequel to X2: "Castle Amber" (1981). Three it directly supports the mad mages of Glantri. And don't go grabbing Mark of Amber from Drivethrurpg as one of the purchasers points out;"Audio CD components are NOT included in the Softcover version of the book. If you want the audio files you will need to purchase the Digital or the Print + Digital combo option. [AND, at the time I write this, there is NO "digital or print plus digital" option, which makes this entire sale pretty much useless.]As Harald H points out below, this module is completely unplayable without the CD! Mr. Welch also explains why in his youtube video."

What we've done with Mark of Amber in the past is to pad out and fill in many of the gaps of X2 Castle Amber. Why?! Because of the super strong connections to Clark Ashton Smith's Province of Averoigne. And one of the things that makes Averiogne so dangerous is it's providence for Lovecraftian monsters. According to the HP Lovecraft wiki entry; ", Smith populates Averoigne with malign and dangerous creatures like vampires ("Rendezvous in Averoigne"), lamias ("The End of the Story", possibly "The Enchantress of Sylaire"), and satyrs ("The Satyr")." Mark of Amber changes the entire landscape of Mystara in many ways and events within X2 Castle Amber come back around to haunt the player's PC's.  For Castles & Crusades's player's PC's Mark of Amber is going to be a big jump into a very large Mystara pond. Played wrong and Mark of Amber could in point of fact see player's PC's time stranded within Averoigne from Mystara. 
Mark of Amber presents a very strong Glantri alternative timeline & into this is going to step one of the most powerful of the Mystara Immortals. And here's where the Castles & Crusades Gods & Immortals is going to come in handy. 

Mark of Amber is going to create a Glantri heavy alternative timeline for Mystara and this might be the point. Glantri wizards & witches recruit the PC's as hirelings to ensure that this timeline comes about. But looking over Mark of Amber isn't going to be a low level campaign level module to go through.  
Mark of Amber is going to create an alternative timeline for the already  convoluted Mystera timeline. Many of the resources for Glantri can come straight from this entry on the Vaults of Pandius..