Robin had always been a government secret agent, working in the SHIELD Initiative, but when she realized that this job was too difficult, she had no choice but to temporarily step out. Now, several years later, Robin is assigned to the case of the infamous Dr. Horrible (Barney, naturally) and called back in to flag him down and finish the job. Avengers/HIMYM/Dr. Horrible crossover.
Rated: K+ - English - Sci-Fi/Friendship - Chapters: 3 - Words: 6,194 - Favs: 4 - Follows: 3 - Published: 2/19/2014 - Barney S., Robin S., Dr. Horrible/Billy - Complete