[1] As of 2019, the series spans 16 novels which document the efforts of the Tanith First, a highly skilled yet unappreciated light infantry regiment of the Imperial Guard, during the Sabbat Worlds Crusade.

Up until Guns of Tanith the Ghosts are mainly pitted against heretical rebels armies, but on Phantine and in most of the campaigns following it they face the well-trained and elite Blood Pact.

While deployed in the theatres of Fortis Binary and Menazoid Epsilon, the Ghosts become embroiled in a plot by an ambitious general officer to supplant Warmaster Macaroth as supreme commander of the Crusade force.

The book also establishes the Ghosts' rivalry with the "Royal Volpone" guard regiment and their commanding officer, Colonel (later General) Sturm, which plays out in the subsequent novel Necropolis.

As the Ghosts withdraw, General Noches Sturm of the Royal Volpone and his adjutant, Major Gilbear, both of whom were disdainful of Gaunt and his "low-born" soldiers, order the Ketzok to bombard the Tanith as they fall back to their base.

First and Only describes how the Ghosts manage to sabotage a Chaos ritual after Lord Militant General Hechtor Dravere orders them on a suicidal attack on an enemy trench line.

Beneath Shrine Target Primaris was a Standard Template Constructor, a relic from over ten millennia before the events of First and Only, which made Iron Men, a pattern of robotic warriors; the traitorous General Dravere, assisted by the mutated, radical Inquisitor Heldane, Colonel Draker Flense and his Jantine Patricians attempted to seize power and overturn the commander of the Sabbat Worlds Crusade, Warmaster Macaroth, using the Iron Men.

However, the machine was corrupted by Chaos and Commissar Gaunt destroyed it, despite the psychic puppetry of the Inquisitor, who died after his "instrument" – Imperial Agent Fereyd, the man into whom Heldane had extended his consciousness – was explosively killed.

The Jantine shock troops annihilated the Tanith Seventh platoon commanded by Sergeant Blane, but were themselves killed to a man by Gaunt's allies, the Vitrian Dragoons.

The Vervun Primary militia prepares to repel the invasion forces, but as Vervunhive's High Master refuses to believe that Ferrozoica has mobilised against them, they are not given permission to arm their defence batteries before the Zoicans fire the opening salvos.

Honour Guard introduces new characters who become central figures in the Tanith First, as well as those who play a key role throughout the Saint arc, such as Commissar Viktor Hark, Ayatani Zweil, Lijah Cuu and Pater Sin.

After the Ghosts successfully infiltrate the Blood Pact's defences and prevent a disastrous loss for the Imperium, Lord-General Van Voytz re-considers his approach on the Ouranberg invasion.

Van Voytz and Count Golke – the Alliance/Imperial liaison – negotiate with Alliance Command and agree to a compromise: one half of the Tanith First is sent to the northern Montorq forests to scout the area, while the other is redeployed to the Seiberq Pocket – the most dangerous section of the war zone – where they are tasked with infiltrating the Shadik lines and destroying the enemy's newly developed siege guns.

Straight Silver is the first novel in which the Tanith First does not see a campaign through to its conclusion: after successfully taking out the siege-guns in the Seiberq Pocket and repelling a Blood Pact flanking manoeuvre in the Montorq Forest, the Ghosts are withdrawn from the front lines and redeployed to Herodor.

Lord-General Lugo – whose career has been unstable since his disgrace at Hagia – plans to use her as propaganda, and does not care that she is an imposter; he believes that he will be forever remembered as the man responsible for a miracle in the Sabbat Worlds.

Lord-General Noches Sturm, the disgraced senior officer relieved of command during the siege on Vervunhive when caught attempting to desert, is captured by the forces of Chaos while en route to a military tribunal.

As enemy psykers work hard to remove the mind-lock, the Imperial forces move quickly to stop Sturm jeopardising the entire Sabbat Worlds Crusade.

By request of Van Voytz and on his own free will, Colonel-Commissar Gaunt leads a hand-picked team of Ghosts to Gereon; a Chaos-held world where Sturm is undergoing an agonising ordeal to recover his memory.

With countless fanatical soldiers and foul warp-beings standing between the rescue team and their target, Gaunt and his men must not only fight for their lives, but also resist the corruption of Chaos that threatens to overwhelm them.

Saved from execution in Camp Xeno on Ancreon Sextus by Junior Commissar Nahum Ludd, Gaunt and the Ghosts are briefly re-united with Lord-General Van Voytz before facing trial by the Commissariat.

The regiment is taking part in the campaign to capture the ancient step-city Sparshad Mons, occupied by the Blood Pact and disturbingly warped nocturnal predators.

The Fifth Crusade Army, led by Lord-General Van Voytz, finally advances to reclaim Gereon from the forces of Chaos after over two thousand days of brutal occupation.

The majority of the Crusade force is deployed to assault the coastline fortifications known as K'ethdrac'tt Shet Magir, an action which the newly inducted Dalin Criid participates in as part of an RIP (Retraining, Indoctrination and Punishment) detail.

As the Ghosts liberate a country town called Cantible, Gaunt is ordered by the Commissariat to make contact with the loyalist resistance in the Gereon Untill, and leads a small team out into the wilderness to do so.

It recounts Gaunt's own mentally internalised struggle to survive after being severely wounded in the events of the previous novel; moments of spiritual communion also establish portents for his future.

The plot of Blood Pact somewhat mirrors that of Traitor General, with Etogaur Mabbon in place of Noches Sturm, but differs with the assassination squad holding the upper hand over their target's captors.

Following the events of Blood Pact, Colonel-Commissar Gaunt and his Ghosts are returned to active duty, and are given one of their most formidable assignments yet; a mysterious space hulk known as Salvation's Reach.

The Tanith First – reinforced with additional troops drawn from Verghast and Belladon – and a trio of veteran Space Marines are sent to neutralise the facility at Salvation's Reach and gather as much intelligence as possible before they destroy it.

After the success of their desperate mission to Salvation's Reach, Colonel-Commisar Gaunt and the Tanith First race to the strategically vital forge world of Urdesh, besieged by the brutal armies of Anarch Sek.

On the forge world of Urdesh, the massed forces of the Imperial Crusade engage in a final bloody battle with the Archenemy commander known as the Anarch, and his elite warriors - the barbaric Sons of Sek.