The Flash Season 5: 3 Ups & 3 Downs From ‘Cause And XS’
Downs...
3. Plot Conveniences
Why did the metahuman cure need 29 days to "cook", exactly? Why didn't Caitlin warn Killer Frost of the incoming dagger like she did the last time Cicada hurled it at her? Why did Team Flash suddenly know all about Nora's time-travel escapades at the beginning of her 53rd attempt to save them (instead of solving it midway through like they did on the previous occasions)? Why could Barry chill in the Speed Force for 60 minutes when it's supposed to be mad at him?
While 'Cause and XS' proved to be a highly entertaining offering, we were expected to take far too many leaps of faith. The show often gets away with the odd convenience for the sake of the plot here and there, especially when it's dressed up with some fancy tech-talk but, as the above questions highlight, these ones were a little over the top.
It's as if the writers don't think anybody will worry about these questions because this was nothing more than a one-and-done story. However, this one-and-done story would have carried a lot more gravity if they actually followed their own rules and stopped changing them when the plot requires them to.