What is this Portal?

Cassie looks through a portal, this is seemly on Earth, and they are using the fleshy heart to get back to Earth and are waiting for Scott to walk through. Later in the trailer we see Scott about to go through, but Kang tackles him.

Full Breakdown Part Two Here: https://reloadreviews.wixsite.com/reload-reviews/post/ant-man-vs-kang-clip-breakdown