Out of all of DC's main Flashes, Wally West just might have the strongest connection to the Speed Force. Over the years, Wally's speed and his skill set have only increased. But when the Flash lost his powers in a fairly strange manner that forced him to rely on his other skills.
This surreal story took place in 2000's The Flash #164-169, by Geoff Johns and Angel Unzueta. One day, Wally woke up in a Keystone City police station while being arrested. Wally was wearing his Flash costume, but he'd lost his powers. Surprisingly, Mick Rory, aka Heatwave, was Wally's arresting officer. Aquaman was even dead, further indicating that the world Wally found himself in was not his own.
In his cell, Wally was rescued by Captain Cold, an unlikely ally who also realized that something was wrong with the world. Wally and Cold fought their way out of the police station to find Jay Garrick, the original Flash. Evidently, however, Jay had died in the army, never becoming The Flash. As a result, no one else in this world ever became The Flash either, and most of the world's heroes had died off as well.
Barry Allen was still alive, working as a regular police officer. This version of Barry tried to arrest Wally and Cold before they were saved by Mirror Master. The villain explained their situation, telling Wally how some mysterious foe wanted to destroy The Flash. Mirror Master and Captain Cold had helped this villain trap Wally in a mirror dimension, but they were trapped in this new world as well with no powers.
Wally, Captain Cold and Mirror Master went looking for answers in the Hal Jordan Museum, where they were ambushed by an assassin named Plunder who confronter the trio with mirror versions of themselves. This fight forced Wally to think on his feet, working with the Rogues to destroy their doppelgangers. The trio defeated Plunder and his boss, The Thinker, and used their technology to return home.
Upon returning to his home dimension, Wally regained his speed. Despite this brief victory, Wally and his foes discovered that Keystone City had been transported to another dimension. Tracking the citizens of Keystone, Wally discovered that this whole plot had been conducted by Brother Grimm, a king from a fairy tale dimension.
When Wally was Kid Flash, he told Grimm that he didn't need to follow in his father's footsteps as a tyrannical king, advice which backfired. Grimm also discovered that Wally had taken up Barry's mantle as The Flash, viewing him as a hypocrite. As revenge, Grimm hypnotized the citizens of Keystone, including Wally's wife, Linda, into becoming part of his kingdom. Together, Wally, Captain Cold and Mirror Master defeated Grimm and saved Keystone.
Ultimately, Wally accomplished a lot despite the loss of his powers. First and foremost, The Flash learned to work with unlikely allies, such as Captain Cold and Mirror Master. The Rogues were quite useful in saving the day, even though they had helped trap Wally in the mirror dimension.
Despite their initial ill intent, Cold and Mirror Master were successful in helping Wally take down villains like The Thinker, transporting between dimensions and saving the citizens of Keystone City. Setting aside their differences, The Flash and his foes saved the day.
When Wally was in the mirror dimension, he also showed how resourceful and smart he could be. In the Hal Jordan Museum, for instance, Wally used some clever strategies to take down the mirror versions of himself and his villains. Wally also took advantage of the weaponry in this museum, using gadgets from Green Lantern villains to defeat Plunder.
Barry Allen might be seen as the smarter Flash, but Wally still learned a lot about thinking on his feet. Learning from Barry, Wally used The Flash legacy to his advantage, while still acting as his own man. Honoring The Flash mantle, Wally also looked to Jay Garrick as a potential ally. Yet when Jay couldn't help him and Barry Allen turned against him, Wally decided to save the day in his own way.