IT'S ALL IN THE CARDS 
(Episode 28)

The gang watches helplessly as Myotismon slips through the gate into the real world to find the eighth child. 

At Gennai's house under the lake, the wise old man gives the kids ten Digimon key cards, which, if played correctly, will open the gate.  Before they can be used, however, the kids must learn the key cards' secret. 

Back at Myotismon's castle, the kids' Digimon battle Dokugumon, the castle's spider guardian and his parasite minions.  At the last second, Izzy cracks the code of the cards and the kids leap through the gate!