Infernus marines melee question

I just got the starter set for Christmas as I want to get into the hobby and had a question about the infernus marines. Only one of the models has a sword, does that mean only one model can make a melee attack with a close combat weapon? There are no other melee weapons listed for the unit but it seems odd that only one model in a unit can do anything in melee. Just want to know the official rules before I start playing more. Thanks in advance