Throughout the game there are instances where Wallace will speak the phrase, "I say!" and here is a quick guide on how to trigger all seven instances.
 When you first walk into town and talk to Mr. Paneer, comment about his searchlight.
 After you receive the weather magazine from the newsstand, go back to Mr. Paneer and use the magazine on him and then comment on the searchlight again.
 When you return to your house, attempt to borrow the umbrella from Duncan.
 When you enter the living room, attempt to pick up the chew toy near the two dogs.
 In the same room, take a picture of Wallace in front of the Hawaiian backdrop and then examine the pictures above the mantle. Select the picture of Wallace in the center.
 After you acquire the mallet from the living room (Mr. Paneer will drop it if you suggest to the Constable that he is a suspect), use it on the Breakfast Gong in the dining room.
 After you acquire the bucket filled with starfish, throw them at Wallace a few times and he will say the phrase for the last time and the achievement is yours!