The Resistance is constructing a portal to another world when they are attacked.
Oliver gets a call from Felicity about the wedding while he is fighting a group of ninjas.
Kara fights a dominator and chats with Alex.
Everyone arrives in Central City for the wedding.
The girls chat while getting ready for the wedding.
Source: What's Filming — Twitter
Kara waits for Alex outside the venue and learns about her sister's night with Sara.