Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
The reason Erna was able to stay hidden from Guido and the Galgad Empire was that Klaus had correctly anticipated the possibility that his school was being bugged.
Source: https://www.cbr.com/spy-classroom-episode-3-spoilers-new-agent-erna-meta-twist/