This week, we look into the science behind Russian opposition leader Alexei Navalny's death, caused by dart frog poison, and why Russia resorted to such an exotic means of dispatch at all. Also, how cat cancer genomics can provide new insights into human malignancies, and - more with a whimper than a bang - how a dying star skipped the supernova and became an instant black hole. Plus, Barack Obama's stance on aliens sends conspiracy theorists into a frenzy... Like this podcast? Please help us by supporting the Naked Scientists