There is no way to get into the locked mansion, but the Mews helicopter will rescue you when you are attacked while kite Surfing.
When you are first recuperating in the mansion, you will talk to Mews, who then goes downstairs. Drink your water and follow him down, going right to the Museum and Lab door. Once there, familiarize yourself with the quest by watching all 5 videos in the museum. When you are done, Mews will appear again. From then on, you will see him at the Lab when you return with clues or proof.
Harold Mews is real only on Poptropica's Cryptids Island.
The Cryptids Museum is on the first floor of the Mews mansion, to the right.
When you come downstairs in the Mews mansion, and enter the museum at the right, your character will suggest watching the 5 videos on the cryptids. So you have to do that before Mews will appear again.
The heliport at Mews' house is out the door, then to your right. You cannot use the helicopter until you have reviewed all of the videos on cryptids and spoken to Mews.
It is one of the locations on the helicopter GPS system on Cryptids Island. Once you are rescued by Mews, review the videos and you can go in search of the four cryptids.
After Mews leaves your room, drink the water and go downstairs, to the museum on the first floor (right). Watch the 5 videos and then Mews will arrive and you can begin hunting for the cryptids in his helicopter.
You awake in the Mews mansion. After he leaves, drink the water, go downstairs, and enter the museum (first floor right). Review all 5 of the cryptids videos and then Mews will join you.
In the museum, first floor right in the Mews mansion.
Go and meet Harold Mews.
Review the 5 videos in the museum, and Mews will appear to give you further instructions.
Go downstairs and to the right, to the Cryptids Museum in the mansion. Look at the 5 videos of cryptids, and Mews will return to give you some instructions.
Take the photo of the "loops in the water" back to Mews.