Simulations of the crossing of the 4:2:1 resonant chain between Ariel, Umbriel, and Titania, obtained setting t_α,2 = 2.3 Gyr, Q₂ = 200, and initial e₄ = 0.0001. Top: evolution of the eccentricities and inclinations of the three moons in the case where the 2:1 mean motion resonance between Ariel and Umbriel is disrupted (case A). Middle: evolution of the eccentricities and inclinations of the three moons in the case where also Titania is captured into mean motion resonance with Ariel and Umbriel (case B). Bottom: evolution of the ratios of the mean motions in both cases.