"A Sad Day" is an hour long special about Geo getting a deadly brain tommer. It is an emotional episodes about Milli's grief and Bot realizing he cant fell sad because he is a soulless hunk of metal with no human emotion. It also includes a heartbreaking ending where Geo dies in Milli's arms. The Troublemakers, Shape bandit and other Team Umizoomi badis also grief about Geo's death and everyone in UmiCity has a big funeral for the fallen hero.
-THis is the last episode
-this episode is rated pg instead of e like the other eps
-THis episode was made due to Geo's voice acter getting older
-This was a controversial episode due to the dark subset and Geo's on-screen death