Why did they travel to uncle Hendricks house number the stars?

In "Number the Stars" by Lois Lowry, Annemarie Johansen and her family travel to Uncle Henrik's house in Denmark to seek refuge and protect their Jewish friend, Ellen Rosen, from the Nazis. The journey is part of a larger effort to help Jewish families escape to safety during World War II. Uncle Henrik's house is located near the sea, which serves as a potential route for their escape. The visit underscores themes of bravery, family bonds, and the fight against oppression.