"Dangerous Currency" is a four-part comic book story that is a crossover between DuckTales and Darkwing Duck. Written by Warren Spector and Ian Brill, and illustrated by James Silvani and Jose Massaroli, it was published across the final two issues of the DuckTales and Darkwing Duck comic books published by Boom! Studios. The four parts of the story were published in the following issues:
Part 1 - DuckTales #5
Part 2 - Darkwing Duck #17
Part 3 - DuckTales #6
Part 4 - Darkwing Duck #18
The story was published without approval from the Walt Disney Company, and it received negative reception from fans, including backlash from former Boom! Kids editor Aaron Sparrow (who plotted the first arc, "The Duck Knight Returns" before being fired). For these reasons, the story arc is not considered canon by Disney, and as such, it is the only story arc from the Boom! Studios Darkwing Duck comic that was not reprinted in Darkwing Duck: The Definitively Dangerous Edition.
Somewhere in the shadows, a manipulative force has spread chaos throughout the cities of Duckburg and St. Canard and it's caught the attention of their two most famous residents, the trailblazing tycoon Scrooge McDuck and the daring do-gooder Darkwing Duck! Can these two larger-than-life luminaries work together to discover the source of the mayhem, or will all be lost in the pursuit of “Dangerous Currency”?
Trivia
Due to Boom! Studios losing the "core four" Disney comic book license earlier in 2011, this was notably the last comic book story featuring Scrooge McDuck, The Phantom Blot, and many of the characters from the Disney duck comics or DuckTales to be published in the United States until IDW Publishing picked up the license. However, between this story and IDW picking up the license, Daisy appeared in the comics published in Minnie & Daisy BFF Magazine, and Donald appeared in comic adaptations of the 2013 Mickey Mouse shorts, published in the Disney Comic Zone Summer 2013 Special. Scrooge also had a cameo in the newly-produced epilogue for Darkwing Duck: The Definitively Dangerous Edition.
This story is also notably, to date, the only appearance of M'Ma Crackshell or Gandra Dee in any comic book story.
The "A" cover for Part 2 depicts Darkwing surrounded by Ma Beagle and the named Beagle Boys from DuckTales, along with Grandpa Beagle, but the story instead uses generic Beagle Boys like those from the original Uncle Scrooge comics.
The "A" cover for Part 3 prominently depicts Flintheart Glomgold swimming in Scrooge's Money Bin with Megavolt, Quackerjack, Liquidator, Magica, and Steelbeak, implying that he is working alongside the other villains. In the actual story, Glomgold is only briefly seen when Donald tells the people of Duckburg to take action against the slime, and he does not appear to be working alongside the villains.
The "A" cover for Part 4 is an homage to the comic book Uncanny X-Men Vol. 1 #101, which featured an image of the cosmic being Phoenix emerging from Jamaica Bay with some of her fellow X-Men. The cover of Darkwing Duck #18 places Gizmoduck in a similar pose (and position relative to the other characters) as Phoenix held.
Drake acts as though he and Fenton have never met before in their civilian identities, but Fenton and Drake previously met when Fenton came to stay at his house in "Tiff of the Titans".
Huey, Dewey, Louie, Webby, Launchpad, and Gyro seem to be well aware that Fenton is Gizmoduck's secret identity, despite that they never actually learned of it on the show. In a similar error, M'Ma Crackshell acts like Fenton never told her that he was Gizmoduck, despite that he already told her in their first appearance.