"Portal" is a magic trick performed by the illusionist David Copperfield, in which he takes a member of the audience and transports both of them to a pre-selected location (Hawaii, the Hoover Dam, Australia, etc.
The effect of the illusion is a disappearance of the magician and an audience member, and their reappearance in the pre-selected location via video feed.
Throughout the show, various audience members are called up on stage to collect various items that Copperfield will supposedly take with him on the "journey".
In the final segment of the show, Copperfield reads the letter of an audience member wishing to be transported to their perfect place.
Subsequently, mist and rain pours down on the audience members as Copperfield returns to the stage to take his final bow.