The fourth book of Heidegger’s ‘Black Notebooks’ is due out very soon – Anmerkungen I-V. Again, there is a missing notebook in the sequence. The volume is not on the Klostermann site, but is on Amazon.de. There is an Italian review here, with some excerpts translated at Enowning – to which I owe this information. [Update – a full English translation is available here.] Sounds like some really grim reading…