Just when it seems that Chase is going to get a big break on the Rex Fury case, Natalia calls in with disturbing news. Black-suited men are watching her, and they seem intent on bringing her in. Hurry to Mercy Hearts Hospital, Chase, before they snag her!
You're still underground, so hop on the speedboat sitting nearby and race out of the sewers. Zip to the nearest dock and get off. Run to the Hospital's waypoint. You'll be just in time -
- to see a bunch of black-suited fellas barricading the Hospital off. Natalia is on the far roof of the Hospital, and you need to get up to her before bad guys do.
Head to the garages with the fires burning out front. Put out the blazes, beat up the guys inside, and crack the nearby safe to get a key card. Use it on the door. Grab the Super Brick inside the elevator and head up to the second level.
Beat up the guys in here and grab dynamite from the vending machine. Use it on the barrel in the next hallway to the right, after you put out the fire, to blow open the windows. Hop through the lower window and break open the object here to get a red pot. Water it to make a vine up to the roof. (You can also go to the second level's outer walkway, along the rim of the Hospital, and find a Super Brick at the far end.)
Beat up the toughs on the third level. You can put out the fires on the right path, but there's a wind machine you can't currently stop. Use the blue bridge across the top of the walkway you blew open to reach some more goons to beat up, a fire to put out and a window to break into. (If you have trouble getting across the bridge normally, scale to the top of the flower you sprouted and use Chicken Glide to sail across to the opposite roof.) Inside this small room you'll find a Red Color Swapper, and if you take out the couch you'll find a Super Brick. Neat.
Make your way back to the wind machine and use the Color Gun to turn the light red, stopping the fan. Do the same on the next one. Put out the fire ahead, then take on the goons beyond.
Natalia will complain for a bit, and Chase will conclude that he can only reach her from the larger section of the Hospital. Great. Break through the door ahead and use the teleporter inside to zip to the glass tunnel beside the building. At the end is a Blue Color Swapper. Use it on the silver wall back in the building to reach a door you can bash through. Run left towards the main building of the Hospital.
Wall jump up the middle of the Hospital. At the top you'll face a few waves of bad guys whom you can easily defeat by tossing them off of the building. Bash open the door here to find the Natalia Kowalski collectible, then use the Chicken Glide symbol to create boost rings all the way down to Natalia. The route is less risky than it looks.
Chase and Natalia will land on the helipad, revealing a Super Build. (You can also find this earlier and it will be marked on your map, though the actual build spot won't appear until Natalia's here.) The Helipad build will easily be financed by the Super Bricks you picked up earlier. If you didn't get them, well, you'll have to backtrack. It costs 20,000 bricks. You'll get a Gold Brick, unlock Helipads, and invite some unwanted attention. Take out the bad guys.
After the goons are finished, order a Swooper from the Helipad and escort Natalia over to Ellie's pad. Moving around as the helicopter is tricky at first, so try to avoid any buildings until you get the hang of it. Natalia and Chase will share some tender words and she'll take off with Ellie. Chase will unlock Crash Pads for stunt landings around LEGO City, unlock a slew of new Super Builds in various locations, and realize that he almost forgot about Vinnie's meeting with his buyer. Yikes! Get on that, police man!