Each year, the staff of Baltimore ad agency Planit puts together a video Christmas card, something cute to send to clients and friends.

This year, the creative directors got a little more creative than usual. They ushered employees into a back room decorated with glittering trees and giant presents and told them to sing carols for the camera.

A few minutes into the song, BAM! — a guy wearing a scary mask and elf costumes popped out of the box.

The reactions are priceless. Some people scream. One woman lurches off with a wreath around her head. One woman whacks the elf with her Santa hat.

What's truly remarkable is that the creative team managed to convince those who had already been surprised to keep the secret.

They got approval from the company's co-founders, saying, "Just trust us. We have a great idea," said Planit's public relations director, Caitlin Mills.

Then they pulled people into the conference room in twos or threes, shooting the video in the afternoons at their Inner Harbor office, when adjacent companies were emptying out.

"We did have some other offices on our floor ask what all the screaming was about," said Mills.

Julie Scharper