It is two years after the end of the Reach invasion. It is Christmas Eve. It is a supposedly-abandoned island in the middle of the Pacific Ocean. It is the rumors of a large and ominous tower cropping up on the island though the land is supposedly crawling with the various failed genetic mutations of several governments. It is Gamma Squad on a reconnaissance – DO NOT engage, ONLY scope out the situation – mission. It is Robin, Wonder Girl, Bumblebee, and Blue Beetle because Nightwing apparently believes them to be the stealthiest available members of the Team.
It is while Wonder Girl is battling Devastation and Robin is dodging the freezing blasts of Icicle, Jr. It is Robin having a free second during the fight and happening to glance over at his blonde teammate. It is him being momentarily stunned by how graceful she can be while simultaneously hitting the villainess and avoiding being hit. It is the panic he feels when Cassie is caught off-guard and Devastation throws her brutally into the wall. It is the anger that he feels when he cannot go help his comrade because Icicle, Jr. refuses to stay defeated.
It is the relief he feels at the end of the mission – they most certainly engaged, and Nightwing will be both angry and proud – when the blonde apprentice arrives safe and sound at the meeting spot. It is the twinkle in her eyes that she has because she's proud of herself. It is the grin that appears on her face when several of the team members give her pats on the back upon returning to base. It is the giggle she emits and the wink she gives him when Nightwing pretends to be furious with him for defying orders.
It is the way she flicks her blonde hair over her shoulder and the way she swings her hips as she walks away, talking to Batgirl and Miss Martian. It is the way he feels something rage-like swirling in his stomach when he sees Cassie vaguely flirting with a smiling Virgil in the living room. It is the relief he feels when Garfield whispers to him that Virgil is dating someone from his civilian life. It is the realization that he cannot wait until the next night's annual Wayne Foundation Christmas Gala – something that he usually dreads – where all the Team will be in attendance and in full formal gear at the insistence of Nightwing and Batman. It is the excitement he feels just imagining how gorgeous she will look in whatever she happens to wear, just as she always does.
It is all of these things (and so much more) that help him discover that he really likes the protégé of his own mentor's best female friend. It is all of these things that tell him that he maybe, just maybe, might be in love with Cassie Sandsmark. And it is most certainly all of these things that tell him that he doesn't mind that idea at all.