The magic shop is very easy to find. Once you exit the station, it is the first building on the right. It is just across from Tubehouse. Magia has a red curtain front with a rabbit above its top hat sign. Inside the shop, approach and talk with the man behind the counter.
This is Liborio Barbadoro. Talk with him to learn more about Richard. Talking with him will reveal what work Liborio and Richard did together. Ask all the questions you can to learn more about what is going on within the sewer. Liborio will give Jensen 3 scramblers to stop the emitters that are keeping the people entranced.