This quest can only be picked up after doing most of Get Junior. An easy way to check is in the middle of Hierarch Square, where you'll find an announcer calling out about the race when it's available. Pick up an invitation to the Memorial Derby off the table near the announcer and read it to start the quest.
Out at the Vegelbud Residence, talk to the race master who'll let you race after you pay the fee of 100 to enter. You can also talk to him to learn a bit about the history of the races if you wish. Note: time will always skip ahead to certain designated times (not always 24 hours apart).
Note that all the races, while different routes, are quite long, so you'll need to keep an eye on Roach's stamina. You'll also need to pay 100 as your entry fee for each of the three races.
For the first two races, you'll earn 10 after you pay each fee and after each win you'll earn 10 and 160 (getting a total net value of 120 if you won both the first time). You'll also earn the Superior racing saddle from the first win and the Rugged saddlebags in the second.
The third race begins like the rest (100 to enter and get 10 ) and you'll be racing against Luc Vegelbud. Note that the weather will always be rainy here, and you'll need to make sure you follow the set path, as there's a "Y" split where neither path is blocked (as you eventually loop back and go the other way).
After you defeat Luc, you'll earn 25 and 200 along with the Superior cavalry saddle. However, as this was also the final race here, you'll also earn an additional 75 and 80 . You might notice though that the quest hasn't completed here. With that, head down the stairs and one of Cleaver's men will congratulate you before giving you a message from Cleaver. Read it, then head back to Novigrad to talk to the gang leader, who'll ask you to enter the Palio race as his entry. Important: once you agree it'll go straight to the race, so don't agree until you're ready and make sure you have a save prior, as you can only do this race once (so if you lose, that's final).
Prepare for a long race: you'll essentially be racing all across Grassy Knoll and then back to the starting point. If you lose, Cleaver will be annoyed but luckily won't do much else (though you don't get any rewards). If you win though he'll be delighted, giving you 700 on top of your race winnings: Racing horse blinders and 40 . Regardless if you won or lost though, the group is soon broken up by the temple guard, who're obviously not happy about all the ruckus. The quest will complete here and you can choose to run off without fighting any guards.
- The Vegelbud family's out-of-town estate was famed not only for its lovely guardians and sumptuous banquets, but also for the series of horse races organized there in honor of one of the line's illustrious ancestors, Erasmus. Geralt, who had spent a great many years in the saddle, decided to test his mettle in this derby - lured, perhaps, by the sizable reward promised to the victor.
- The Vegelbud races segued into an unexpected encore. Cleaver, one of the[sic] Novigrad crime lords, was so impressed by the witcher's riding prowess that he offered him the chance to take part in the equally famed (though illegal) race organized by the local underworld.
- If Geralt wins the Palio:
- Though the nighttime race was rife with obstacles, Geralt managed to win it as well. Sadly, he was not given long to celebrate his triumph, for the city guard, alarmed by the ruckus of galloping horses at an hour when decent people should be asleep, broke up the event and scattered its participants.
- Talk to the master of ceremonies for the Vegelbuds' race.
- If one takes a break between races:
- Talk to the master of ceremonies to begin the race.
- Beat the first rider.
- Beat the second rider.
- Beat Luc Vegelbud.
- Read the letter you received.
- Talk to Cleaver about the letter.
- If you initially say no:
- Return to Cleaver and talk to him about the race.
- Be the first past the finish line.
- If you fail the Palio race, you'll miss out on the Fast and Furious achievement.
- This quest is put on hold during a section of the quest Carnal Sins.