Guenever's chamber has no glass windows, but iron bars on it. That night, Lancelot finds a ladder in the garden and climbs to her window. They speak, about Arthur and their betrayal of him, about Lancelot's God and about Guenever's childlessness. While they speak, Lancelot cuts the iron bars out with his hands and spends the night in her bed.
The next morning, Guenever sleeps late. Sir Meliagrance is impatient for her to leave and so, finally, enters her chamber to wake her. However, he sees blood all over the sheets (from Lancelot's hand with the bars) and quickly accuses her of having had one of the wounded soldiers in her bed. The accusations escalate and Lancelot, who enters, demands that Meliagrance either forget his accusations or challenge the Queen's champion. This Sir Meliagrance does and it is agreed that he and Lancelot will fight.
It is ironic that Meliagrance rightly accuses Guenever of being unfaithful to the king—but choses the wrong knight with whom she has been unfaithful. Lancelot quickly defends her, but feels conflicted by it because he knows Meliagrance's accusation is fundamentally right.
Sir Meliagrance asks Lancelot if they can remain cordial despite their impending fight because he wants to show Lancelot his castle. This they do until they come to a chamber with a trap door. Lancelot falls sixty feet through the trap door onto a bed of hay; Meliagrance hides his horse and tells Guenever that Lancelot has already set off for Camelot.
Meliagrance's plan to imprison Lancelot is surprising—up until this point he is simply depicted as a bumbling, idiotic knight.