The Survivor's Magnifying Glass. useful to a clue minded investigator who needs something to do with his/her hand. The net effect of +1 is not always a worthwhile bonus but depending on your character and other cards you may stand to gain a lot if you can hit the magic numbers (2 above the difficulty for Standard, 3 for Hard). Wendy Adams can put this to use till she gets her Lockpicks, the other survivors all suffer intellects of 2- or preferable alternatives. For them Flashlight is a better pure-investigation tool.
But Lantern has an extra use. Automatic damage! Autodamage is always good, a guaranteed dead Swarm of Rats or Acolyte can be absolutely critical, or as a finisher to a foe that you managed to tag with a punch or to end a foe that you've chipped at with a proper weapon. This is the real kicker for this card, say for example you hit someone with a .45 Automatic leaving them with 1 hitpoint, say you wanna avoid some particular tokens in the chaos bag, the Lantern got you covered.
A note unmentioned in a review of this card insofar.
A -1 Shroud value will affect tertiary card effects, by this I mean Double or Nothing, Lucky!, "Look what I found!" ETC.
I.E, if you reduce a 3 difficulty location to difficulty 2 and fail, your minimum value (0) ensures that you can play "Look what I found!" on the test you just failed by 2 points.