Here is the preview:
Now for even bigger news. Barry will make a trip to National City for a cross over event into an episode of Supergirl on CBS on March 28. This crossover can be huge for all the DC TV series, but officially links Superman/Supergirl into the Flash/Arrow reality. Personally, I can't wait for Hal Jordan to show up as Green Lantern (remember his disappearance was mentioned in The Flash when Barry did his initial test runs at Ferris Air's airstrip).
Here is the link to the news: