In "Conscience Does Make Cowards of Us All," how does Tova get Marcellus back in his tank?

When Tova sees that Marcellus is on the shelf above the tank, she scrambles to the top of the table. When she is face-to-face with Marcellus, she speaks to him and tells him that she is going to help him down. Marcellus latches onto Tova's arm and he makes his way along the shelf as Tova limps along the length of the table. When she gets him over the tank, she asks Cameron to move the cover. Cameron moves it as wide as it will go. Marcellus drops back into the tank.