Emily Guerrero (unbeknownst to her) was a Human with Inhuman lineage. When the Terrigen Cloud came to Emily's area, it affected her entire family and each of them were engulfed into cocoons. Emily emerged from her cocoon knowing that she had undergone some kind of metamorphosis. Eight months passed, and Emily, now going by the name of Synapse, became a member of Commander Steve Rogers' Avengers Unity Division as a representative of the Inhumans.
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Despite being unprepared for the public eye and life as a superhero, Rogers insisted that Emily stay with the team and vouched for her abilities, even though there was some tension with fellow member, Rogue, who was a mutant. Synapse's first battle as an Avenger was against the Super-Adaptoid.
During the scuffle she tried to read the adaptoid's mind but to no avail, so she used her telepathy to control a flock of pigeons to attack it while the rest of the team were able to finish it off for good.