Republican presidential candidate Donald Trump during the third night session of the Republican National Convention in Cleveland. BRENDAN SMIALOWSKI/AFP/Getty Images

The fourth and final night of the Republican National Convention is all about the GOP’s presidential nominee: Donald J. Trump.

Trump has been a presence every night of the convention. He introduced his wife, Melania, on Monday; briefly addressed delegates via video Tuesday; and helicoptered into Cleveland Wednesday to appear on stage with vice presidential nominee Mike Pence – and, of course, stare down rogue Republican Ted Cruz.

But tonight is Trump’s big moment – indeed, one of the biggest moments of his presidential campaign. The big question: which Trump will show up? The on-message candidate who reads off the TelePrompTer? Or the Trump who ad-libs, riffs off the crowd, and strays from the campaign’s message of choice?

Trump will speak in prime time. He’ll be introduced by his daughter, Ivanka. Other major speakers include:

-Silicon Valley venture capitalist Peter Thiel. According to member station KQED, Thiel is expected to tell delegates that he is “proud to be gay.” The convention approved a socially conservative platform earlier this week that decried same-sex marriage.

-Oklahoma Governor Mary Fallin

-Republican Party Chair Reince Priebus

-Liberty University President Jerry Falwell, Jr., an early Trump endorser