Ep 10. Chain of Command (Part 1)

Captain Jean-Luc Picard has temporarily left the Enterprise and been replaced by Captain Edward Jellico, who immediately rubs the crew the wrong way with his brusque manner and speech patterns. The Enterprise has been sent on a mission to retrieve a Cardassian intelligence officer who has information on a new weapon the Cardassians are developing. To aid in the mission, Starfleet assigns an officer from another ship, Commander Riker's old acquaintance, Captain Shelby. Shelby's brash attitude and aggressive tactics further ruffle feathers among the Enterprise crew.

Meanwhile, Picard has been sent on a secret mission to locate and infiltrate a Cardassian base. His team includes the quiet and reserved Lt. Commander Data and the tough, no-nonsense Chief Petty Officer Jellico. While the team prepares for their mission, Picard is briefed on his assignment – he is to go undercover and pose as a member of a resistance group led by the notorious Gul Madred, who is suspected of working on the new weapon.

As Picard and his team prepare to land on the Cardassian planet, back on the Enterprise, Jellico is instituting major changes. He has ordered the ship's decor updated to look more militaristic, he has instituted several new security protocols and he changes the duty schedule, forcing Commander Riker to work a different shift than usual. Riker doesn't take kindly to the changes and tensions between he and Jellico continue to rise.

On the planet, Picard's team is doing its best to blend in with the Cardassian society. They frequent the local bar, where they encounter a Cardassian man, Vashen, who takes an interest in Picard's apparent fearlessness and willingness to speak his mind. Picard charms Vashen, who seems convinced that Picard might be useful to their cause. However, the team's chance to get close to Gul Madred hits a snag when they discover that the Gul has been replaced by another Cardassian official.

Back on the Enterprise, Jellico's changes in command structure begin to have a more significant impact. The ship is attacked by a Cardassian vessel and Jellico orders the use of the more aggressive phaser power setting. This move proves to be successful in fending off the attack, but has caused major concern for several members of the crew, including First Officer Riker.

As Picard and his team regroup and adjust to the changes in their mission, the situation back on the Enterprise becomes more tense. Jellico orders a second mission to retrieve the intelligence officer from Cardassia, but his methods are questioned by Commander Riker. Ultimately, Jellico's refusal to negotiate and his insistence on aggressive tactics lead to tensions reaching a boiling point, with Riker and Jellico clashing in a heated argument.

The episode ends with Picard, Data and Jellico still on the planet, unsure of how to proceed, and the crew of the Enterprise left to navigate the shifting dynamics of a changing command structure.