This trick is done immediately after the training mission but before the briefing. This secret modifies the briefing. After getting up to the ship, look at the hatches on the main deck. This is the deck where the bridge and all the living quarters are located. Looking where the drop ship bay is found (on the main deck), to the left is a hatch just before you turn the corner. Open the hatch to find a Seagoat. You can interact with it by "using" it. Enter the following responses in this exact order: "Spam", "Spam", "Spam", "HumBug". You will see a "Lincoln is pleased" message. Go to the second deck to your briefing. Pay close attention to the distress call.