For every migrant who makes it to Europe, dozens fail to complete what can be a difficult and dangerous journey. Marie Keyworth travels to Senegal to hear the stories of two men who did not make it beyond Libya, having crossed Mali, Burkina Faso and Niger, and their feelings about having failed to complete the critical last leg - the boat journey across the Mediterranean. She also speaks to Seydine Ken and Jo-Lind Roberts from the International Organisation for Migration - which organises voluntary returns - to find out why people leave in the first place, and why they hope that fewer of them will make the perilous trip in the future. (Photo: Returning Senegalese migrant Hassan Odjo)