When Roswaal happily tells the story of how his romance with Echidna began 400 years ago, Beatrice rebukes him for casually calling it a "romance." Ryuzu interrupts to comment that Echidna saved her, as well. The one thing these three very different people share is their gratitude toward Echidna. But their days spent in both amicable and argumentative conversation about Echidna are brought to an end by one man's arrival.
you can repay that by working 
your hardest, I suppose.
يمكنكِ أن تردّي الجميل ببذل قصارى
جهدكِ، على ما أفترض
trabajen para devolverle el favor.
esforzaos para devolverle el favor.
potrete ripagare la vostra fortuna
impegnandovi al massimo, oserei dire.
você pode pagar por isso
trabalhando, imagino.