Signs ( audio story ) Publisher ' s summary . River Song is on the trail of the mysterious , planet - killing SporeShip s . Nobody knows where they come from . Nobody knows why they are here . All they do know is that wherever the SporeShips appear , whole civilizations are reduced to mulch . But River has help . Her companion is a handsome time - travelling stranger , someone with specialist knowledge of the oddities and dangers the universe has to offer . For Mr Song has a connection to River ' s future , and he would never want his wife to face those perils alone . . . Plot . The story opens with River bedridden . Mr . Song is explaining to her how she absorbed radiations while saving a planet from the SporeShips . He tells her that she is dying . River and Mr . Song are trying to disarm a SporeShip . Mr . Song checks his Five - Hundred Year Diary because he ' s excited to be older than River for once . He doesn ' t help River to disable the ship because he says it ' s against the rules , and he suggests her to write a book about SporeShips . In the end , River succeeds . Back in Mr . Song ' s ship , named " Sarah Jane " , River complains about the fact that she ' s dying . She says that she wouldn ' t be if she had kept her regenerations for herself . She wonders who she ' d be if she hadn ' t met the Doctor . She ' s also worried that she ' s losing her memory . Mr . Song propose that they forget about the SporeShips and go to Florana instead , but River is determined to solve this mystery . River has strange dreams in which she wanders through the ship . She hears someone calling and sobbing but she can ' t find them . She thinks the ship is like a haunted house with ghosts . She wakes up and tells the Doctor she has to find the right balance between taking enough medications to prolong her life but not too much so she can still think . Mr . Song prepares tea , describing every step of the concoction in a poetic way . River points out it looks like the description of a universe . River and Mr . Song explore one of the planets of the Goldilocks . Mr . Song finds a sort of " tomato - banana " that he names " tombola " . River refuses to taste it , saying she ' s hungry but she can ' t face food . She thinks that the planet is a lovely place that will be a good home for a species someday . She has a theory about the Spore Ships . They used to think that they were destroying planets randomly , but River has noticed that they never chose planets that didn ' t already had life on it . She thinks that they have a plan . They visit a Planet Delva 98 that has been wiped out by a SporeShip two thousand years ago . Mr . Song describes it as an " empty planet where it ' s always raining " . River is taken aback by the fact that there are trees and a sort of grass while there shouldn ' t be anything , and takes off her helmet to try the atmosphere , which is breathable . She states that two thousand years is too short for a planet to get back to life . Then , River and Mr . Song are attacked by an army of big spiders . They cover them and get inside their suits . They can ' t get rid of them until River has the idea of setting themselves on fire - the suits are fire resistant . River analyzes the atmosphere and discovers that it ' s full of protein chains . As they go back to the shuttle , River and Mr . Song see that a line of spiders are standing in their way . They set the spiders afire again and use a remote control to get back inside . River wants to explain Mr . Song her new theory but he wants her to rest . She insists and says that maybe the SporeShips are wiping out the planets that house civilisation about to get out of control . They choose the ones that haven ' t developed space travel yet . She wants Mr . Song to think about it and then consent to rest . River dreams again that she ' s walking in the huge ship . She wonders what happened to the TARDIS . There ' s a mysterious door . She ' d asked Mr . Song about it , but he ' d replied there wasn ' t any door . She knocks at the door , and one day someone knocks back . When she wakes up , she wants to find the next planet the SporeShips are going to strike and prevent it . She tells the Doctor to rule out the systems where the SporeShips have already struck , the ones with no life and the ones that have already developed space travel . Then they look for the ones where the civilisation is getting interested into space travel and " whose hobbies include making things go boom " . They head for the nearest one . After reaching Planet Unity , River and Mr . Song start arguing over what they ' re going to say to the people . In the end , River gets to make the speech . She warns them about the SporeSphip and assure them she and Mr . Song will destroy it for them - but then Mr . Song lets her know they have no weapon . She , therefore , encourages them to come together to face the SporeShip instead of killing each other . Mr . Song and River wonder if the people of Unity will make it . As the SporeShip arrive , they see Unity ' s weapon powering up and preparing to attack , but they quickly realise they ' re actually targeting the " Sarah Jane " ship . They try to convince the people to wipe out the SporeShip once again but it ' s too late , the planet is destroyed . River dreams of Mr . Song preparing sandwiches and talking non sense . When she wakes up , her state is decreasing . She ' s in pain while the medications is increasing and she can ' t think properly . Mr . Song says it ' s okay for her to go , but she doesn ' t want to leave him . He tells her goodbye but at the last moment , she decides she can ' t leave with one final mystery unanswered . River dreams again . This time she ' s giving a lecture about the SporeShips . She has three theories about it . Her favourite one says that an ancient race created them because their time in the universe had been too short and they didn ' t want anyone else to enjoy it . But it can ' t be right because they could never have hoped to destroy that much life . The second one states that " the Spore Ships are leftover weapons from the war that wiped out the last universe , or that they ’ ve slipped back from the end of this one " . But she thinks that assuming whoever is behind this is acting out of hatred is wrong . Instead , she believes those who are using the SporeShips , the first people , are destroying the planet that are developing in the wrong way , like a gardener cuts off the seedlings . Then , River feels dizzy . She realises that her audience is composed of incarnations of the Doctor . She says she doesn ' t know if she ' s alive or dead , but she clings onto love . The Doctors applaud her . At this moment , she sees an intruder - Mr . Song . When she wakes , Mr . Song is next to her . She accuses him of holding her diary in her dream . She tells him he must never read that book and makes him promise he ' ll burn it after she ' s gone . She falls asleep again . She ' s running in the " Sarah Jane " , but this time someone is after her . That persons manage to grab her . Mr . Song and River eat together , and suddenly River asks why she ' s not dead . Mr . Song says he ' s very grateful for it and takes his diary to look the answer up into it . River orders him to put it down . Actually , it ' s her diary with a false cover . She knows the Doctor would never read her diary and she understands that he ' s an impostor . The ship is indeed his and he ' s a member of the first race that created the SporeShips . She demands the truth from him and he finally explains that he became bored with his people and he wanted to stop the SporeShips . He joined the Rulers of the Universe . River was invited to their party so she could meet him . There ' s a flashback of the end of the Rulers ' party , during which River was drugged and kidnapped by Mr . Song . He used her diary to act like him . River says she has one more thing to show him . River lead him to the door in her dream . She stops to catch her breath , takes off her shoes and starts running to the door . She threatens to open it and send Mr . Song and herself into space if he doesn ' t give her answers . She has nothing to lose because she ' s dying . She wants to know if the Rulers will use the SporeShips for themselves , but he refuses to answer . She ' s about to open the door when she disappears , leaving a puddle on the floor . Mr . Song doesn ' t seem alarmed . River wakes once more , Mr . Song at her bedside . He pretends they ' re going to hunt the SpaceShips together , but River doesn ' t buy it . This time , she ' s the real River and not one of her clones . She had escaped from the cloning chamber . She wants him to show his real face because she prefers killing things to people , and he does . She shots him , and then says she ' s going after the Rulers .