Agents of S.H.I.E.L.D.'s 100th episode, 'The Real Deal', was a celebration of everything the series has achieved over the past five seasons. It faced Coulson and his team with the threat of a so-called "Dimension of Dreams," one that brought their worst fears to life. That meant the episode featured a wide range of cameos, from villains like Hive and Lash to allies such as Deathlok.

But there was a lot more to 'The Real Deal' than just the cameos. In the build-up to the 100th episode, Elizabeth Henstridge had teased that there would be "so many, just gorgeous Easter eggs." Those comments left eagle-eyed fans poring over every scene, eager to spot the promised Easter eggs. It didn't take long to spot a single scene that was unusually rich in them. There's an entertaining moment when Deke heads into a pawn shop, and the camera lingers on the window. It's filled with objects that are tied both to the show's history and to the wider MCU.

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Take A Look In The Window

It's a blink-and-you'll-miss-it moment, but most of the objects in the window are actually Easter eggs. There are three references to the wider MCU; there are Hulk and Iron Man masks that call back to Spider-Man: Homecoming, and action figures of Thor and Hawkeye. Amusingly enough, the Thor action figure is actually holding Heimdall's sword. The Bifrost blade has typically been associated with Heimdall; intriguingly, an action figure for Avengers: Infinity War sees the God of Thunder wielding Hofund. Some fans have speculated that it could suggest Heimdall will die in Infinity War. Similar action figures were, of course, featured in the pilot episode of Agents of S.H.I.E.L.D..

The rest of the objects are more directly associated with Phil Coulson, though, and will be familiar to any long-running fans of Agents of S.H.I.E.L.D.. Let's go through the Easter eggs from left to right.

Probably the most emotional Easter egg is the cello, a nod to Audrey Nathan. Before his death in The Avengers, Coulson had become close to cellist Audrey Nathan, but their romance came to an abrupt end when Loki stabbed him through the heart. S.H.I.E.L.D. told Nathan that Coulson was dead, and he felt unable to reveal himself. Fans finally met Nathan in the Season 1 episode "The Only Light in the Darkness," when she was pursued by the insane Marcus Daniels.

Moving along, the ax is the same one used by Mack to sever Coulson's hand, saving Coulson's life when he touched an Inhuman Obelisk. Hanging from the ceiling is a model airplane, which appears to be the S.H.I.E.L.D. Globemaster model Coulson kept aboard the Bus in Season 1. Underneath this is a red hoverboard, and that's possibly the most sophisticated Easter egg of all. Hoverboards played a key role in the Back to the Future trilogy, and Season 5 has explored the theme of time-travel, with S.H.I.E.L.D. now attempting to avert a dystopian future. It's also possible this could be an amusingly meta nod to Coulson's red automobile, Lola, which can switch to hover-mode.

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The baseball bat is a reference to one of Coulson's other ill-fated lovers, Rosalind Price. In Season 3's 'Among Us Hide', Rosalind showed Coulson one of her prize possessions, a baseball bat signed by Frank Robinson and Mickey Mantle. Finally, the "Grumpy Cat" mug was a recurring joke in Season 1; it had been brought on board the Bus by Fitz, and Coulson called it out in the episode 'FZZT'.

Elizabeth Henstridge was absolutely right; 'The Real Deal' really is filled with "gorgeous Easter eggs." In a single blink-and-you'll-miss-it moment, Agents of S.H.I.E.L.D. offers callbacks to key moments and characters in Coulson's history. It reminded fans of his connection to the Avengers, of his past relationships, and of the injuries he'd suffered in the course of duty. This is the kind of detail that really makes the 100th episode shine.

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Agents of S.H.I.E.L.D. continues Friday March 16th with “Principia” at 9pm on ABC.