Alita told her friends not to rescue her, if she was captured. With the Kandrona lamp blueprints leaked, the Empire's days on this planet are numbered. Her friends and allies in the movement just need to stay out of trouble long enough to build new pools, to accept with open arms all who are free to desert, now that the Empire's monopoly on food for Yeerks is broken.
Visser Three lowers her into the box, and she feels the lid slam shut above her as he announces the sentence. <Death by Kandrona starvation--the penalty for treason by sympathy with a subject species>. She bashes her head against the wall in desperation, but doesn't dare try to morph--even in death, she can't give away the peace movement's other secret weapon.
You can't sing, in a Yeerk's native electrical communication modality, but you can recite poetry. She recites the lines of the Battle Hymn of the Republic, translated into the Yeerk language, into the empty water as the strength slips away from her body and cold and pain close in on her.