diff --git a/pom.xml b/pom.xml
index e58f095..2bc4582 100644
--- a/pom.xml
+++ b/pom.xml
@@ -36,6 +36,7 @@
     <picocli.version>4.3.2</picocli.version>
     <pdfocr.version>1.0.2</pdfocr.version>
     <term4j.version>0.4.0</term4j.version>
+    <tika.version>1.24.1</tika.version>
   </properties>
 
   <dependencies>
@@ -67,28 +68,31 @@
       <version>${picocli.version}</version>
     </dependency>
 
-    <!-- PDF manipulation -->
+    <!-- Document reading -->
     <dependency>
-      <groupId>com.itextpdf</groupId>
-      <artifactId>itext7-core</artifactId>
-      <version>${itext7.version}</version>
-      <type>pom</type>
+      <groupId>org.apache.tika</groupId>
+      <artifactId>tika-core</artifactId>
+      <version>${tika.version}</version>
     </dependency>
     <dependency>
-      <groupId>com.itextpdf</groupId>
-      <artifactId>pdfocr-root</artifactId>
-      <version>${pdfocr.version}</version>
-      <type>pom</type>
+      <groupId>org.apache.tika</groupId>
+      <artifactId>tika-bundle</artifactId>
+      <version>${tika.version}</version>
     </dependency>
     <dependency>
-      <groupId>com.itextpdf</groupId>
-      <artifactId>pdfocr-api</artifactId>
-      <version>${pdfocr.version}</version>
-    </dependency>
-    <dependency>
-      <groupId>com.itextpdf</groupId>
-      <artifactId>pdfocr-tesseract4</artifactId>
-      <version>${pdfocr.version}</version>
+      <groupId>net.sourceforge.tess4j</groupId>
+      <artifactId>tess4j</artifactId>
+      <version>4.5.1</version>
+      <exclusions>
+        <exclusion>
+          <groupId>org.slf4j</groupId>
+          <artifactId>jcl-over-slf4j</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>org.slf4j</groupId>
+          <artifactId>log4j-over-slf4j</artifactId>
+        </exclusion>
+      </exclusions>
     </dependency>
 
     <!-- Terminal output -->
diff --git a/src/main/java/eu/mulk/aendggner/AendGgner.java b/src/main/java/eu/mulk/aendggner/AendGgner.java
index 618f36f..e510efb 100644
--- a/src/main/java/eu/mulk/aendggner/AendGgner.java
+++ b/src/main/java/eu/mulk/aendggner/AendGgner.java
@@ -1,7 +1,13 @@
 package eu.mulk.aendggner;
 
-import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.List;
 import java.util.concurrent.Callable;
+import org.apache.tika.config.TikaConfig;
+import org.apache.tika.exception.TikaException;
+import org.apache.tika.io.TikaInputStream;
+import org.apache.tika.metadata.Metadata;
 import picocli.CommandLine;
 import picocli.CommandLine.Command;
 import picocli.CommandLine.Parameters;
@@ -14,10 +20,10 @@
 public class AendGgner implements Callable<Integer> {
 
   @Parameters(index = "0", description = "The base text to modify.")
-  private File baseFile;
+  private Path baseFile;
 
-  @Parameters(index = "1", description = "The diff relative to the base text.")
-  private File diffFile;
+  @Parameters(arity = "*", description = "The diff relative to the base text.")
+  private List<Path> patches;
 
   public static void main(String... args) {
     int exitCode = new CommandLine(new AendGgner()).execute(args);
@@ -25,8 +31,19 @@
   }
 
   @Override
-  public final Integer call() {
-    System.out.println("Hi.");
+  public final Integer call() throws TikaException, IOException {
+    var tika = new TikaConfig();
+
+    for (var file : patches) {
+      var metadata = new Metadata();
+      metadata.set(Metadata.RESOURCE_NAME_KEY, file.toString());
+      try (var is = TikaInputStream.get(file)) {
+        var mimetype = tika.getDetector().detect(
+            TikaInputStream.get(file), metadata);
+        System.out.printf("File %s is %s.\n", file, mimetype);
+      }
+    }
+
     return 0;
   }
 }
diff --git a/src/main/java/module-info.java b/src/main/java/module-info.java
index e7d9c77..dbe7d62 100644
--- a/src/main/java/module-info.java
+++ b/src/main/java/module-info.java
@@ -1,3 +1,6 @@
 module aendggner {
   requires info.picocli;
+  requires org.apache.tika.core;
+  requires java.sql;
+  opens eu.mulk.aendggner;
 }