When yoursquore on a secret mission secret messages are key and thatrsquos why you need the message dart refill you can write secret messages with the special pen on the 8 reusable message darts and conceal them until itrsquos time to reveal them then you can erase the messages and write new ones without the double decoder nobody will be able to guess your secretsr includes 8 darts pen and double decoderr special pen for writing secret messagesr double decoder reveals your secre