Despite a mostly disappointing season for an otherwise great series, this episode manages to conclude the series decently. Being lured to a construction site, the clan was on their way to help a trapped victim only to find out it was a trap. The bomb blows up causing the beams to fall on top of the clan, Angela and Bronx were the only survivors for getting to the site too late.
Xanatos later reveils to Elisa that the clan is safe as he knew of the plot and added a secret compartment to protect the clan from the falling debris until it was safe to move them out while leaving stone remains to make the destruction more believable.
The rest of the clan goes off in search of the train where Angela and Bronx were being transported on. The Quarrymen lead by Castaway were on route to attack the train. Castaway disables the train while the bridge was destroyed. Goliath saves the train by breaking off the engine's connection to the other cars while Brooklyn shows his leadership with his idea to use the Quarrymen's jet packs to slow the train down.
In the end, the people aboard the train all were grateful for the Gargoyles in saving their lives from Castaway's reckless actions that could've killed them all. And Goliath gives his final monologue and thus ends the show.
In a way it was moving as it wasn't just the end of the series, but also at least it was a nice send off for the heroes as perhaps now the humans would be more tollerant of the Gargoyles.