The Signal Reading Order

This reading order is designed to give an outline of major storylines featuring the Signal (Duke Thomas) throughout DC Comics. It may not encompass every one of his appearances, but is a timeline of the major ones and the stories that affect them.
The continuity details relating to each specific storyline are explained in the “Review” of each storyline. Every “Review” link will provide a detailed continuity breakdown of that story and will explain any reference the story makes to other aspects of the DC Universe. All of this can be found under the “Continuity” section of each link.

Jump to: New 52 – Rebirth – Universe

New 52

Duke Thomas was introduced in DC’s New 52 era. He does not have any appearances before this point.

Duke’s first appearances are in the Batman: Zero Year story arc. These simply introduce Duke at a point several years before the present. Later on, Duke make his first few major appearances in the Batman series. After that, he becomes a main character in the We are Robin comic and continues to play a supporting role in the Batman series.

Batman issues are from the Batman Vol. 2 series.

Notes

1. Batman #21 marks Duke's first ever appearance in DC Comics. Though this appearance amounts to little more than a cameo, it is included here simply because it is his first ever appearance.
2. Duke's appearance in this issue marks his first meeting with Batman. It is not a major factor in either person's life but is brought up again in the future.
3. These additional issues are included in order to explain what is going on in these two storylines. Technically, one could just read the essential issues listed here and get the gist of what Duke is doing. However, these additional issues explain what happens in between Duke's appearances and provide context for the story as a whole. If you are just looking to understand Duke's story by itself you can skip these, but if you are looking to understand the story that Duke is a part of then these issues are necessary.

Rebirth

The transition from the New 52 to the Rebirth era does not include any significant continuity changes for Duke Thomas. Duke's story picks up where it left off at the conclusion of the Batman series and heavily references what happened to his family during the Batman: Endgame (Reading Order) event.

In this era, Duke takes on a minor role in the Batman series, where he can be seen helping Batman and spending time with the Bat-family. However, the All-Star Batman series is the first time Duke takes on a starring role in a series, as he is the main character in this comic's backup story. In this series, his training process is shown, he partners with Batman on a few missions, and the conclusion introduces a major development that impacts his character going forward. After this, Duke's appearances in the prelude to the Dark Nights: Metal (Reading Order) event further elaborate on aspects from the All-Star Batman conclusion.

Batman issues are from the Vol. 3 series
Nightwing issues are from the Vol. 4
Detective Comics issues are from the Vol. 1 series

Notes

1. These issues of are mostly about Batman, with Duke playing a small supporting role. They show Duke helping Batman or the Bat-family but do not have much of an impact on his overall character progression.
2. These issues of Batman are, once again, mostly about Batman. However, they feature a few members of the Bat-family meeting and working on the upcoming threat posed by Bane (Reading Order), a central plot point from Tom King's run on Batman (Reading Order).
3. Duke's appearance in this issue is very quick. However, it highlights his feelings about some members of the Bat-family.
4. Duke's role in this issue of Batman is similar to his role in Batman #16. It has the Bat-family meeting to discuss a problem and has Duke as one of the people at the meeting. Though Duke's role here is minor, it may be interesting for fans looking to see him interact with the Bat-family more.

Universe

The Universe era is essentially an extension of the Rebirth era and, as such, does not introduce any significant continuity changes for Duke Thomas. Duke's story picks up where it left off at the in the prelude to the Dark Nights: Metal (Reading Order) event.

In this era, Duke has a prominent role in several comics and finally takes on a superhero name, the Signal. His first major appearance is in Batman and the Signal, a comic that focuses on Duke's first major attempt at solo crimefighting and the mysteries he began to uncover in the previous era. From here, he becomes involved with the Outsiders team-up. The team's first appearance is in the "On the Outside" story arc from the Detective Comics series but, after that, they star in their own series, Batman and the Outsiders. Finally, Duke plays a small part in the Dark Nights: Death Metal (Reading Order) event. Alongside these major appearances, Duke also makes brief appearances alongside either Batman or the Bat-family.

DN:DM = Dark Nights: Death Metal
The Unexpected issues are from the Vol. 3 series
Detective Comics issues are from the Vol. 1 series
Batman and the Outsiders issues are from the Vol. 3 series
Batman issues are from the Vol. 3 series

Notes

1. Duke makes a guest appearance in this issue of The Unexpected. It features him as a prominent character but is generally unrelated to most of his other adventures.
2. Duke's appearance in this comic is very brief. However, it connects to his role in the general storyline stretching through this Detective Comics story arc.
3. Duke's appearance in this comic is brief. However, it features him discussing his growth and progress with Batman for a moment, which some fans may enjoy seeing.
4. Duke appears alongside several members of the Bat-family in the "Batman's Greatest Case" story from this issue. The story features a short but fun moment shared between the entire Bat-family.
5. In these issues, Duke makes rather brief appearances alongside other members of the Bat-family. These simply show the part Duke plays in the Bat-family's conflict with Bane (Reading Order).
6. Duke plays a very small role in these issues from the Dark Nights: Death Metal (Reading Order) event. However, we've included these issues here to show that he was present and helping in the event's final few chapters.
7. Duke plays a very small role in these issues from the Batman: The Joker War (Reading Order) event. However, we've included these issues here to show that he was present and helping in the event's final few chapters.
8. This entire story arc is mostly about Batman and Damian Wayne (Reading Order). However, Duke and other members of the Bat-family appear in several issues from this arc. They play a small role in the first two issues but play a much smaller role in the second two. Fans can easily skip these issues without missing much, in regards to Duke's overall storyline.

 All DC Comics Reading Orders