This chapter of our Spider-Man Miles Morales solution describes the Underground Undercover quest. Phin will take you to the hideout. After this adventure you will unlock the skill of Venom Dash and learn the location of the remaining three Underground hideouts.
Location: Hell's Kitchen
Rewards: 4500 XP
Meet Phin at a café in Hell's Kitchen. After a short cutscene, she will take you to the Underground hideout. Follow her, jump from the crane to the roof and enter their lair. After a while Phin will have to leave. This is your chance to look for clues about the location of Nuform. Scan your surroundings and interact with the objects you find.
You will hear the Underground members talking about a meeting on the lower level of the building. Go towards the railing. After the next cutscene, disguised as Spider-Man, jump through the vent back to the hideout. You will find yourself in the Underground training room. Use the camouflage, mark all your opponents with the visor and get rid of them one by one.
Once you have cleared the room, approach the monument and move it. You will find a hidden passage underneath. Go down the stairs and move down using the crane. Go across the ceiling to the next room. After the cutscence you will start another fight.
This time you will learn the ability of Venom Dash, very useful for taking out opponents who wield swords. Defeat everyone and jump out of the building to complete the mission. While browsing the map, you will also unlock the locations of the other three Underground hideouts.