It's not that they didn't have reason for doing so--they were on stake-out and the whole story has a strong plot, with events unfolding in a logical manner. And, despite the fact that most of the heroes spend most of the story standing idle, there's still plenty of action peppered throughout.
It begins in Avengers 194 (April 1980). The team is regrouping after finally getting a judge to agree that they didn't require government oversight on everything they did. This is an interesting issue--there are a few pages to set up the story that will really begin in the next issue, but most of it is fairly quiet interactions between the various characters. There's a few not-so-quiet interactions as well, such as the Vision working out some of his frustrations in the Mansion's training room.
It's the sort of issue that would probably be a terrible one to use to introduce a new reader--there's simply not enough happening to interest a reader who isn't familiar with the characters. But for a regular reader, it's great stuff. David Michelinie, the writer, does a truly magnificent job of giving each of the Avengers a distinct personality and them having them play off each other in believable ways. Marv Wolfman is the only other writer from that era who had a comparable talent in this area.
It doesn't hurt to have an artist like George Perez making everything--even the quiet scenes--look awesome.
Anyways, a guy named Selbe shows up at Avengers Mansion, claiming that someone is trying to kill him. But he's an escapee from a mental institution and, when guards from that institution show up with a court order, the Avengers are obligated to hand him over. Most of the Avengers are okay with this--Selbe really did seem to be a visitor from Crazy Town. But the Wasp isn't so sure this is all on the up-and-up. She goes off on her own to investigate.
In Avengers #195, the other Avengers follow her. This is where the stake-out begins--they don't have enough evidence to just blast their way into the institution, so Yellowjacket (Hank Pym's current identity) and guest-star Scott Lang (the new Ant Man) sneak in for a look. In the meantime, Michelinie gives us more great character interaction as the Avengers wait for better information before taking action.
Hank and Scott soon find out a lot of stuff:
1) Wasp is being held prisoner.
2) Selbe is a fast-grown clone whose heart is going to be removed to save the life of the elderly head administrator.
3) The institution isn't for mental patients, but its main purpose is to train henchmen, who are then hired out to various supervillians. The whole "cloning someone to provide a heart donor" thing is simply a side issue.
It's this last part that makes this a favorite story of mine. Villains in various comic book universes all seem to have an endless supply of henchmen. I suppose if we thought about it, we'd simply assume that the henchmen are being recruited from whatever low-level criminals happen to need work. But when you think about it, in a comic book universe there is money to be made in training henchmen and then contracting them out to guys like Doctor Octopus. Henchmen are essentially cannon fodder--even if your evil plan works, you are probably going to lose a fair amount of your guys to the superheroes, SHIELD or the cops. So you are going to need a regular supply of replacements. It's a real need and there's money to be made filling that need.
(I also love a line of dialogue from one of the school administrators who is evaluating a student: "This one will never do. His I.Q is way too high. Almost normal.")
Moving on with the story: Yellowjacket and Ant Man spring the Wasp and we get plenty of action as they take out a bunch of henchmen and try to spring Selbe. But that goes awry when the head of the school shows up and takes all three of them down.
This is the first appearance of Taskmaster, a villain who is effective for several reasons:
1) George Perez gives us a great visual design for Taskmaster.
2) His "photographic memory" origin--allowing him to replicate acrobatic and fighting moves perfectly after seeing them once--is clever and original.
3) His villainous philosophy is refreshing. He's not driven by ego or revenge, but he's in it simply for the money. He'll fight you and kill you to protect his commercial interests or to make an extra buck, but he otherwise has no problem with running away. Taskmaster has a completely mercenary outlook on life--an action is either profitable or not profitable. That's his only decision-making criteria.
Now this isn't a criticism of great characters like the Joker or Lex Luthor, whose actions often are driving by revenge, ego or pure insanity. These things are appropriate for those characters, but it is refreshing to run into someone like Taskmaster every once in awhile. For him, it's all about the money.
In Avengers #196, the elderly administrator dies of a heart attack before getting his new heart and the Avengers are alerted to danger by some ants sent by Scott. (Another bit of cleverness--the ants obviously can't talk, but when they swarm over Iron Man's face plate for no reason, it's not hard for the Avengers to deduce that its likely a call for help.)
This story arc appeared in 1980, towards the tail end of the era in which comic books made a real effort to simply be fun. That doesn't mean there wasn't good characterizations and the occasional dose of tragedy or angst when these were needed. But pick up an issue of a Marvel or DC comic at the time and odds are the writer and artist were making a real effort to tell a fun story. Whether or not they were successful in any one story, they all got an A for Effort.
But soon we would have Mutant Massacres and endless Crises and rapes and destroyed marriages and heroes who become anti-heroes for no good reason at all. The success of The Dark Knight Returns and The Watchmen would spill over into the mainstream comics and everyone would simply forget how to have fun.
That's a slight exaggeration, of course. There are still writers out there who remember the concept of fun. A few years ago, the kid-friendly Marvel Adventures series was wonderful--especially their Avengers book. Today, Batman '66 is a book brilliantly recreating the world of the Adam West TV series. There always seems to be one or two worthwhile superhero books on my pull list. And over the past few decades, animated cartoons such as Batman: The Animated Series or (more recently) Avengers: Earth's Mightiest Heroes have been great. So there's still good superhero stories out there. Perhaps the concept of having fun will make a comeback in the bulk of the mainstream books. I'm not holding my breath, but it could happen.