Alone Among the Couples: Grandpa Max’s state of mind at the start of the episode. Adding insult to injury, Gwen mentions that St. Lewis is where he met their Grandma.
Forklift Fu: Gwen uses a forklift truck to fight against one of Vilgax's robot drones.
I Choose to Stay: Both times Xylene asked Max to come with her to explore the galaxy together, Max turns it down. The first time, it was to watch over Earth and defend it from alien threats. The second time, he chooses to stay because his grandkids need him.
Literal Metaphor: "You're going to eat it! ...Literally eat it. That's your power."
The Reveal: Xylene was the one in the spaceship transporting the Omnitrix back in "And Then There Were 10". Not only that: she meant for the Omnitrix to find it's way to Max, not Ben.
Tomato in the Mirror: Later on in the story, Ben is frustrated as to why Xylene doesn't approve of his ownership of the omnitrix if she sent it to him in the first place. The answer is she didn't intend to send it to him: she was trying to send it to Max. At hearing this, Ben is rather devastated that in the grand scheme of things, getting the watch was a mistake.
Diamondhead: If I'm such a mess-up, then why did you send the watch to me in the first place?
Xylene: I didn't send you the Omnitrix. You found the Omnitrix before it reached its intended recipient.
Diamondhead: What?
Xylene: The pod containing it veered slightly off its intended course.
Diamondhead: I got the watch by mistake?
Xylene: Of course. You didn't believe that I would purposely send the most powerful device in the universe to a child, did you? I was sending it to Max.
