The author gives almost continual daily entries - and that's exactly how the narrative is presented - that track the progress he and his comrades, of the elite Grossdeutschland unit, make. There's a lot of detailed frontline action. I was hoping to say it probably helped his chances of survival that he was in a mortar unit, as you might imagine that they would be slightly behind the sharp end, but I've been somewhat disabused of this notion, inasmuch as mortar positions were as often as not on or forward of the front line. Not during attacks, necessarily, but very much so during the longer periods between attacks.
Mortar ammunition runners, and such was Rehfeldt's lot, also had the risky job of to-ing and fro-ing between the mortar pits and rearward supply areas, fetching fresh ammo. Indeed, it was running this dangerous gauntlet during an attack that would earn the author an Iron Cross, second class. This book (and doubtless its companion second volume) are terrific for learning about grunt-level tactical warfare on the Ostfront.
One striking thing is that it's very early on in the book, and Barbarossa itself, that the German's reach their farthest east, with the author and his fellows southeast of Moscow, around Tula, at which point the tide turns and retreat begins. Temperatures reach -52°, and Rehfeldt is invalided out of the line twice, due to severe frostbite which, along with near ubiquitous diarrhoea and vermin, reminds one of the horrors of Napoleon's 1812 invasion of Russia.
Grossdeutschland, with its famous stahlhelm unit insignia, was way more than decimated. Losses were nigh on - indeed it's suggested here they exceeded - 100%! In other words more men were killed, injured or otherwise lost (captured, missing, etc.) than made up the full-strength of the unit pre-combat. As a result they are amalgamated into other units during the campaign, before being withdrawn for rest and refitting, and restored at greater strength, ready for Operation Zitadelle, the Kursk offensive.
I'm posting this review as I near the end of volume one. It's been brilliant, and continues to be exciting, informative and highly compelling. I'm really looking forward to the second instalment! To conclude, I'll do something I don't usually do in my reviews, and quote an extended extract, to give a flavour of Rehfeldt's writing .
 This is one of several weapons I'd not been aware of before reading this account. N.B. the pic is not from this book.
 I think it's worth noting that the translation is excellent. One hears the Germanic turn of phrase, the rhythm, sentence construction, etc. But English vernacular is also well deployed, where appropriate, using such phrases as 'hell for leather' and 'hit the sack'.
The above Bundesarchiv photo, not from the book, shows the Grossdeutschland armband quite clearly. I'd expected it to look more like the top of the two examples below. But it's more like the bottom one, i.e. harder to decipher! Can anyone decipher and explain exactly what the GD cuff thing says, and why it differs from what one might expect?