Over the course of five seasons of The Flash, Barry Allen has learned the ins and outs of time travel, and his own mistakes have taught him the consequences of traveling through time. In this week's episode, Nora broke the rules of time travel 52 times but hasn't faced any consequences for her actions - yet.
In The Flash season 5, Team Flash has come close to beating their latest nemesis, Cicada, on more than one occasion, but each time he has managed to escape their grasp. Barry believed that they could defeat Cicada by taking away his powers with Cisco's metahuman cure. The problem was that Cisco's cure wouldn't be ready for use for another month. To speed up the process, in "Cause and XS" Barry took it with him into the Speed Force, leaving the safety of Central City to Nora for the span of one hour.
During this time, Cicada kidnapped Iris, and when Nora tried to save her, Killer Frost was killed by Cicada's dagger. Nora reacted by "rewinding time", giving her another chance at stopping Cicada. However, her actions caused Elongated Man to die in Caitlin's place. Nora failed time and time again to stop Cicada until her 53rd try when she finally told Team Flash what was going on and together they put together a plan to defeat him. At the end of the episode, Barry warned Nora of the dangers of time travel, but seemed to believe that this time they had escaped unscathed. The timeline is still in tact and no one died.
Surely, Nora is breaking The Flash's time travel rules? Barry certainly wasn't as lucky as his daughter when he rewound time in season 1 to stop a tsunami from destroying Central City; Flash saved the city, but his decision to mess with the timeline did have some unfortunate side-effects. Reverse Flash told him that if he prevented one tragedy, another would always occur in its place. Of course, Barry's biggest mistake involving time travel was "Flashpoint", where he prevented the murder of his mother, causing an uncalculated number of massive changes to the timeline.
These events have taught Barry valuable lessons about time travel. He has come to understand it can come with a hefty price, and has explained this to Nora in an earlier episode. Nora, unlike Barry, broke the time travel rules in a much more extreme way. Just like Barry's mother, Caitlin was supposed to die, but Nora prevented this from happening, and repeated the same hour 52 more times, eventually finding a timeline free of tragedy.
Considering how much other characters have talked about the damage a person can cause to the time stream by altering a single event, one can only imagine the amount of problems Nora could have inadvertently created. Fortunately for the heroes, if contrived for the show, Barry and Nora's conversation at the end of the episode suggests that nothing in the episode will have any consequences. Hopefully, this won't be a case of The Flash ignoring its rules and Nora's tampering with the time stream will somehow come back to haunt them in a later episode.
The Flash returns to The CW on March 5.