Wild Magic Plus The Black Star

There are two stories. Wild Magic and The Black Star. Wild Magic: At age fourteen Carma discovers that she has magic powers. She applies for mage training and is accepted, but she soon fails because her magic is wild and uncontrollable. The Grand Wizard could train her to control her powers, but claims it would take too much time and effort. She is sent home with a bracelet that nullifies her powers. Three years later the grand Wizard sends for her and asks her to go on a critical and dangerous mission. Of all the wizards in the kingdom, she is the only one who might stand a chance of succeeding...because of her wild magic.
The Black Star. Hiram, a royal courier, is tricked into accepting a ring with a death curse. Whoever possesses the ring during a full moon dies. To rid himself of the curse he must find someone who will willingly accept the ring from him. To throw it away would mean death. He refuses to trick an innocent person int accepting it, He has only a few days to figure what to do with it.