Rowling, J. K. Year ... at Hogwarts #6

Sequel to: Harry Potter and the Order of the Phoenix

Other minister -- Spinner's end -- Will and won't -- Horace slughorn -- Excess of Phlegm -- Draco's detour -- Slug Club -- Snape victorious -- Half-blood prince -- House of Gaunt -- Hermione's helping hand -- Silver and Opals -- Secret riddle -- Felix Felicis -- Unbreakable vow -- Very frosty Christmas -- Sluggish memory -- Birthday surprises -- Elf tails -- Lord Voldemort's request -- Unknowable room -- After the burial -- Horcruxes -- Sectumsempra -- Seer overheard -- Cave -- Lightning-struck tower -- Flight of the prince -- Phoenix lament -- White tomb

Sixth-year Hogwarts student Harry Potter gains valuable insights into the boy Voldemort once was, even as his own world is transformed by maturing friendships, schoolwork assistance from an unexpected source, and devastating losses

Sequel: Harry Potter and the deathly hallows