In case you skip it...

As the first episode of season three, “Evolution” introduces a few changes:

• Worf has been promoted from Lieutenant Junior Grade to full Lieutenant.
• Geordi has been promoted from Lieutenant to Lieutenant Commander.
• Dr. Crusher is back from Starfleet Medical and is once again the Enterprise’s Chief Medical Officer. Dr. Pulaski has transferred elsewhere.
• Fancy new uniforms!

  

Also, in this episode, Wesley accidentally creates a race of sentient nanomachines dubbed “nanites.” They leave the Enterprise and adopt a presumably-uninhabited planet as their homeworld.