If you leave the zone, such as zoning into the Spire: your Fellow will disappear and you will have to wait until after JP midnight to retry the quest.
Your Adventuring Fellow will get an experience point bonus of 80 XP for each mob that you kill up to 30 mobs, you will also get a bonus for each of the ??? spots that you examine until you chose to end the quest at one of them.
The maximum bonus that you can get is 4800 XP.
When you select to end the quest, your Adventuring Fellow will give you the option to send you back to the entrance of the Promyvion zone.
(Optional) Set weekly RoE objective: Vana'versary -> 15th Vana'versary IV -> A Strong Fellowship (W) before following the below instructions to receive the Tactics Pearl.
Once you have completed the quest, return to a city Rendezvous Point and your Adventuring Fellow will give you a new Tactics Pearl (If you still have one in your inventory, you will be unable to access any of the options at the Rendezvous Point until you drop it from your inventory.)
(Optional) If you examined at least 2 ??? spots and have completed Mixed Signals (Fellow Genkai 3), you will also be given a piece of homemade food depending on his/her personality type.
If you fail the quest for any reason, you can return to a Rendezvous Point in any of the Promyvion zones after JP midnight to try again.
You can start this quest again after a conquest update from when you received the Tactics Pearl.