Arthur meets Guinevere, the woman of his dreams. Morgan and King Lot conspire to attack Camelot and take the throne. Merlin has Arthur reclaim the legacy sword in the stone to prove his worthiness as king.
Known here as the sword of Mars, to prove his worthiness as king. It is hinted at that Merlin has rigged the contest in advance so that only one who first pushes the sword in can then pull it out, while he suggests to Arthur that this is how to retrieve the sword. Merlin uses Arthur's success as propaganda to inspire loyalty to Arthur.