This anthology of stories featuring Jonathan Maberry's character Joe Ledger has several stories in which the contributors have Ledger meeting their own characters.
In Jon McGoran's "Strange Harvest," Ledger and McGoran's detective Doyle Carrick investigate a pharmaceutical corporation.
In Scott Sigler's "Vacation," Ledger, vacationing in San Francisco, is asked to investigate the murder of two DEA agents. Inspector Lawrence “Pookie” Chang takes Ledger to the mansion of a possible suspect, Jebediah Erickson. Chang and Erickson are from Sigler’s novel Nocturnal.
In Larry Correia's "Psych Eval," the Department of Military Sciences must deal with a demonically possessed agent. Agent Franks has been contacted and is on his way. Franks is from Correia’s Monster Hunter International series.
In Jeremy Robinson's "Prince of Peace," an enigmatic group takes Joe Ledger and Chess Team’s Jack Sigler prisoner. Chess Team is the subject of a series of novels by Robinson.
In James R. Tuck's "White Flame on Sunday," Ledger joins forces with monster hunter Deacon Chalk to combat a Sumerian elephant cult. Like Ledger, Tuck’s character Deacon Chalk has several solid links to the CU.
Dana Fredsti's "Crash Course" features Ledger in the world of Fredsti’s Ashley Parker series, which takes place after a zombie apocalypse. Obviously, this would be an AU.
These crossovers are among the hundreds covered in my book Crossovers Expanded: A Secret Chronology of the World Volume 3, which will be published by Meteor House! All three volumes are AUTHORIZED companions to Win Scott Eckert's Crossovers: A Secret Chronology of the World Volumes 1 and 2!