That's Eoin Colfer and Rick Yancey, two of my favorite authors. Both are known for fantastical adventure series and had a new book come out yesterday, May 7, 2013.  Both books are starts to new fantastical adventure series.  Yesterday was a good day.
W.A.R.P.: The Reluctant Assassin by Eoin Colfer
Riley has been pulled into the FBI's covert W.A.R.P. operation (Witness Anonymous Relocation Program). He and young FBI Agent Chevie Savano are forced to flee terrifying assassin-for-hire Albert Garrick, who pursues Riley through time and will not stop until he has hunted him down. Barely staying one step ahead, Riley and Chevie must stay alive and stop Garrick returning to his own time with knowledge and power that could change the world forever.
The 5th Wave by Rick Yancey
After the 1st wave, only darkness remains. After the 2nd, only the lucky escape. And after the 3rd, only the unlucky survive. After the 4th wave, only one rule applies: trust no one.  Now, it's the dawn of the 5th wave, and on a lonely stretch of highway, Cassie runs from Them. The beings who only look human, who roam the countryside killing anyone they see. Who have scattered Earth's last survivors. To stay alone is to stay alive, Cassie believes, until she meets Evan Walker. Beguiling and mysterious, Evan Walker may be Cassie's only hope for rescuing her brother—or even saving herself. But Cassie must choose: between trust and despair, between defiance and surrender, between life and death. To give up or to get up.