The two teenagers, aged 12 and 13, were intensely sought after leaving a school in San Fernando and not returning to their homes. They appeared after 11.30 in the morning in San Juan and Boedo, in good health.

Their phones were switched off and the movements of a SUBE card were the clues that relatives and investigators were following. The possibility that the absence was aimed at fulfilling a challenge from the social network TikTok is not ruled out by the researchers. But a letter left by the missing boy to another classmate had left everyone baffled.