Update (1310ET): Not even a quarter of the way through roll call, and Kevin McCarthy (R-CA) has failed to secure enough votes to become Speaker of the House - which will push the contest into a multiple-ballot vote.

What's next? As Politico reports:

After McCarthy fails to get 218 votes on the first ballot, the Freedom Caucus antagonists have signaled that they will start backing another yet-unnamed candidate on the second ballot. The Daily Beast reported Monday night that that person is Ohio Rep. JIM JORDAN, the longtime McCarthy critic-turned-ally.