After saving the galaxy from the villainous Ronan, the Guardians of the Galaxy -- Peter Quill (Pratt), Gamora (Saldana), Drax (Bautista), Rocket (Cooper) and Baby Groot (Diesel) -- are thrown back into cosmic action when they crash land on a planet after their ship is attacked by drones. There, Quill's mysterious father, Ego (Russell), makes contact and offers Quill the truth of his heritage. Ego reveals that he is a god-like being of incredible power and that his son holds within him the power to alter the shape of the entire cosmos.
When Earth's fossil fuels are exhausted, a major corporation called Alterplex builds a massive tower capable of tapping into the limitless energy of a mirror universe called "The Echo." When bizarre anomalies begin to occur on a global scale, astronaut Will Porter (Stevens) is recruited by Alterplex to travel through a portal, where he must activate a device designed to stabilize the connection between the two Earths and save both realities. However, after teaming up with Abigail (Marlohe) and Michael (Gernandt), two Alterplex employees, he begins to realize that his mission isn't exactly what he was led to believe.
Not long before her 12th birthday, Siren Phillips (Perry) learns a shocking truth: that she is far from an ordinary girl and will turn into a mermaid on her birthday. While she says her goodbyes to her friends, including a cute new boy at school (Grazer), a sinister group of mermaid hunters finds her trail and becomes committed to catching her before she makes her final transition to life in the sea.