So these two H atoms are basically abstracted, and they are placed onto the Fad. And so then we form the double bond between these two carbons to form that fumar rate. And this process actually is at equilibrium. It has a Gibbs free energy value of zero kilojoules per mile under the conditions that we find in ourselves. Now, in step seven, this is a hydration step, and it's catalyzed by fumarase. And what fumarase does is it basically attaches a hydroxyl group from water onto this side, and the H ion is attached onto this side.